3/2019
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PRODUCT NEWS
Maxim’s Bi-directional Current Sense Amplifier with PWM Rejection Offers Industry’s Highest Accuracy and Fastest Settling Time for Greater Motor Efficiency MAX40056 provides 0.3 percent accurate, full-scale direct winding current measurement, over 4 times faster than competition. Designers can now improve motor efficiency and reduce vibration using the MAX40056 bi-directional current sense amplifier with patented pulse-width modulation (PWM) rejection from Maxim Integrated Products, Inc. This high speed, wide-bandwidth amplifier extends Maxim’s industry leadership in precision, high-voltage current sense amplifiers into motor control applications.
Creating a motor control system requires precise current sensing and measurement of motor winding currents. A commonly used approach is to infer winding currents by performing ground or supply referenced measurements in the bridge circuit. Direct winding current measurement is a simpler and more accurate method, but the implementation is challenging due to the high common mode swing of the PWM signal. Adoption of this approach has been limited by poor PWM rejection and slow settling speed of existing solutions. MAX40056 rejects PWM slew rates of greater than 500V/μs and settles within 500ns to provide 0.3 percent accurate, full-scale winding current measurement. The patented PWM rejection scheme achieves 4 times faster settling time than competitive offerings, allowing motor control designers to increase drive frequency or decrease minimum duty cycle without sacrificing measurement accuracy. Higher PWM frequency smoothes out the current flow and reduces torque ripple, resulting in more efficient motor operation. Accurate winding current measurement at low duty cycle helps reduce or virtually eliminate vibration when the motor is running at a slow speed. MAX40056 has a wide common mode voltage range of -0.1V to +65V and a protection range of -5V to 70V to ensure the inductive kickback does not damage the IC. With bi-directional sensing capability, it is ideal for DC motor control, base station, datacenter, battery stack and many other applications which require precise current measurements in noisy environments. Key Advantages • Fastest Settling Time: patented technique rejects common mode PWM signals and yields fastest settling time within 500ns. • Highest Accuracy: accurate direct motor winding current measurement at 4 times higher PWM frequency or 4 times lower duty cycle than competitive offerings. • Increased Performance: improved motor efficiency and reduced vibration. Maxim Integrated | www.maximintegrated.com www.international.electronica-azi.ro
CONTEST
Win a Microchip SAM L11 Xplained Pro Evaluation Kit
Win a Microchip SAM L11 Xplained Pro Evaluation Kit (DM320205) from Electronica Azi International. The Microchip SAM L11 Xplained Pro Evaluation Kit is ideal for evaluating and prototyping with the ultra-low power SAM L11 ARM® Cortex®-M23 based microcontrollers. The new SAM L11 MCU features Arm TrustZone® for Armv8-M, a programmable environment that provides hardware isolation between certified libraries, IP and application code. Microchip enables robust security by including chip-level tamper resistance, secure boot and secure key storage which, when combined with TrustZone technology, protects customer applications from both remote and physical attacks. The SAM L11 Xplained Pro Evaluation kit features a microBUS socket and Xplained pro extension headers to expand the development with Mikroelektronika click boards and Xplained pro extension kits. The kit also includes an on-board Embedded Debugger and a Xplained Pro Analog Module(XAM) that can be used with the Data Visualizer tool to monitor and analyze power consumption in real time. The Pro Evaluation Kit supports all SAM L10/11 MCUs by the Atmel Studio 7 Integrated Development Environment (IDE), IAR Embedded Workbench, Arm Keil® MDK as well as the Atmel START. Microchip’s QTouch® Modular Library, 2D Touch Surface Library and QTouch Configurator are also available to simplify touch development.
For your chance to win a Microchip SAM L11 Xplained Pro Evaluation Kit, visit: http://page.microchip.com/Elec-Azi-Int-SAML11.html and enter your details in the online entry form. 3
Electronica Azi International » TABLE OF CONTENTS
3 | CONTEST: Win a Microchip SAM L11 Xplained Pro Evaluation Kit
30 | Leuze: Sensor solutions for AGV 32 | FUJIFILM UVSCALE: Visual verification of ultraviolet light amount distribution
6 | How wireless is a smart home? 8 | Why and How to Expand Microcontroller Program Memory with SPI XiP Flash
33 | Sensor Instruments: Welding Seam Detection with Edge Detectors
12 | New Innovations in Data Converter ICs
34 14
14 | Mix & math
34 | INXPECT: INDUSTRIAL SAFETY - LBK System 36 | Leuze: Precise measurement, positioning, quality
17 | CONTEST: Win a Microchip SAM L11 Xplained
assurance of objects
Pro Evaluation Kit
36
17 | CONTEST: Win a Microchip SAM L11 Xplained Pro Evaluation Kit
37 | Contrinex: Transparent-object sensors with 18
18 | Passive Filter Design Concept of Buck Regulators for Ultra-low Noise Applications
patented UV technology detect presence of clear plastic sheet during thermoforming 37 | Sensor Instruments: Choose the Right Side 39 | SAKI Corporation Introduces Ultra-fast, Inline, 2D Bottom-side automated Optical Inspection for PCBs
22 | Keeping trains moving 26 | Thermal imaging cameras
40 | Martin offers an innovative solution to gently
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Electronica Azi International is published 6 times per year in 2019 by Euro Standard Press 2000 s.r.l. It is a free to qualified electronics engineers and managers involved in engineering decisions. Copyright 2019 by Euro Standard Press 2000 s.r.l. All rights reserved.
Electronica Azi International | 3/2019
WIRELESS
How wireless is a smart home? By Bernd Hantsche, Director Embedded & Wireless
ZIGBEE AND WLAN In order to be able to control roller blinds, air conditioning or lamps not only via a smartphone but also via virtual private assistants (VPA), such as Alexa, Siri, Google Assistant, Bixby or Cortana, as well as other devices, like smoke detectors, alarm clocks or surveillance cameras, all the interconnected devices form a system that is usually connected via interfaces of the supplier clouds. Using these interfaces, a radio alarm clock can, via a WiFi network, receive the music from the Internet to wake you up in the morning and send a signal to Alexa to gradually increase the brightness of the bedroom light. Communication between the VPA and the light source usually takes place via a ZigBee WLAN gateway or directly via WiFi. The advantage of this solution is that WiFi 6
Now that the first smart devices have found a new home in apartments and houses, the focus is not only on networking with the Internet but also on interconnecting with each other. Depending on what you want to achieve, other wireless standards are recommended here.
lamps do not require an extra device for communication but connect directly to the home WiFi router. Disadvantages are a relatively high level of standby power consumption and additional data traffic in the WLAN network. In very smart households, this can lead to a situation where the available data rate is no longer sufficient. As a result, some suppliers use the ZigBee Light-Link protocol. It consumes less power than a WiFi connection and does not additionally load the WiFi network with data throughput. Compared to wireless technologies, such as ANT or Bluetooth 5, however, the level of power consumption is still relatively high. In addition, a ZigBee network occupies 5MHz in the 80MHz-wide 2.4GHz frequency band. This can cope with either three WiFi networks or 16 ZigBee networks in parallel, as well as combinations
of both, e.g. two WiFi networks and five ZigBee networks. Too many networks result in frequency overlaps and thus to a drop in performance; for a short while, the network may even come to a complete standstill. THREAD The thread protocol has recently made its way into more and more smart home applications. Since it supports the Internet protocol version 6 (IPv6), it offers many advantages over proprietary, locally restricted addressing. The brains behind the protocol is the Thread Group, a non-profit organization whose members include a number of large engineering companies. Several alliances are available for the application profiles, including the ZigBee alliance with its dotdot solution. This is a kind of universal language for the Internet. Electronica Azi International | 3/2019
DESIGN SOLUTIONS » SMART HOME
tocol as an intermediate level to support large networks with numerous devices. This Bluetooth protocol is also supported by smartphone compatibility, relatively low power consumption, and very low latency thanks to a flooded instead of a routingbased mesh structure.
If the radio alarm clock is to be able to control devices from different suppliers – e.g. also switch on the TV set to watch breakfast television – it is advisable to already integrate the thread protocol from the start to guarantee future interoperability, at least with regard to the hardware requirements. BLUETOOTH With Bluetooth 5, the Bluetooth Special Interest Group has also introduced operating modes that are of interest to smart home applications: For instance, the 2Mbps mode allows the transmission of video signals, e.g. from the camera of a robotic lawn mower or the door monitoring system. A 500kbps and a 125kbps mode enable increased transmission power and a longer coding of the individual bits, thereby ensuring wireless signals can be transmitted across several hundred meters and through several walls. In contrast to technologies based on IEEE802.15.4, such as ZigBee and Thread, Bluetooth 5 is already available in modern-day smartphones and is, therefore, also suitable for direct smartphone connection. An addition to Bluetooth 5 is from Bluetooth 4.0 the Bluetooth Mesh 1.0 prowww.international.electronica-azi.ro
ANT AND ENOCEAN If you want to go one step further, the radio alarm clock will not only turn on the music and the bedroom light, but it will do so at the ideal moment. It determines this with the aid of a smartwatch or fitness tracker, which is aware of the wearer’s sleep phase through pulse and movement detection. For the alarm clock to have access to these devices, it needs the ANT protocol. As this has become established with such devices; only a few exceptions work with Bluetooth. The reason for this is that ANT is the ultimate most economical wireless technology for sensors in the immediate vicinity – and thus perfect for all applications that can be operated with button cells or similar small energy storage devices for months and years without having to charge or change batteries. Only the EnOcean sub-GHz standard is even more energy efficient. The protocol is not as efficient as ANT, but thanks to the patented energy harvesting extensions for the use of kinetic energy when operating switches, solar energy or thermal energy difference, EnOcean wireless technology makes it possible to do entirely without a separate energy storage system. EnOcean switches can already be found, for example, in Weber prefabricated houses. An existing light switch can also be used to tell the radio alarm clock that you are about to go to bed and to start a sleep timer. NFC However, if a device is equipped with all these wireless technologies, it is not exactly user friendly. As end users need to set up all the connections to their devices and systems. Near Field Communication (NFC) provides a helping hand in this situation. This means end customers only need a smartphone and must touch each device to be connected just once in order to set up the networks. EVERYTHING IN ONE MODULE Developers are therefore faced with the task of integrating all these wireless standards into the application. With the nRF52840 System-on-Chip (SoC) from
Nordic Semiconductor, this is very simple indeed: The all-in-one solution offers not only a powerful microcontroller with wireless units for ZigBee, Thread, Bluetooth 5, Bluetooth Mesh, ANT, and NFC, but also a USB port. In addition, there are A/D converters for evaluating other sensors, encrypting data transmission, and protecting memory areas. The SoC is in fact only a little bit more expensive than a plain ZigBee solution. At the heart of the nRF52840 is a 32Bit ARM® Cortex™ M4F processor running at 64MHz. Its on-Chip memory (1MB flash and 256kB RAM) provides enough space for simultaneous, multiple wireless protocols. The SoC also features high-resolution RSSI measurement and functions, such as EasyDMA, which reduce processor load and enable direct memory access. To lower the power requirements, all peripheral components feature clock and power management to ensure that they are turned off when not in use. The cryptographic coprocessor ARM® CryptoCell310 provides a high degree of security. It supports a random number generator and many asymmetric, symmetric, and hash cryptographic services. Moreover, the coprocessor accelerates operations, saves CPU processing time, and reduces power consumption.
The nRF52840 is on-air compatible with Nordic Semiconductor’s nRF24, nRF51, and nRF52 series products. Anyone who now misses the big EnOcean advantage can use an nRF52-based module that is compatible with EnOcean energy harvesting modules. This is available from Rutronik, as are solutions for all other wireless technologies. The wireless experts support customers when choosing the ideal solution for their individual application. Rutronik www.rutronik.com 7
MICROCONTROLLERS
Why and How to Expand
Microcontroller Program Memory with SPI XiP Flash By: Rich Miron Contributed By Digi-Key's North American Editors As microcontroller applications get more complex, developers are using more Flash program memory for the application firmware. This is especially true with Internet of Things (IoT) endpoints that are starting to perform relatively complex edge computing. However, sometimes applications can expand to the degree that external program memory is required, at which point developers need to choose between parallel or serial Flash. Adding an external parallel Flash memory chip ties up I/O lines, adds complexity, and consumes extra board space. This article will describe how to expand a microcontroller’s Flash program memory by adding an external serial Flash memory chip from Adesto Technologies that supports an SPI eXecute in Place (XiP) interface. It will also explain how XiP Flash is mapped into the memory space of a Microchip Technology microcontroller so that code execution is almost transparent to firmware. Reasons for external memory expansion Where possible, developers should start application development by selecting a microcontroller that has a roadmap of pincompatible devices with more memory. If during development the application firmware expands to exceed the Flash memory on the target device, a pin-compatible device with more Flash can be easily substituted during development. This allows the application memory to expand without having to redesign the pc board 8
for a different microcontroller. However, the application may require more program memory than is available on-chip for a pin-compatible microcontroller family, requiring the use of off-chip Flash memory. This is becoming more common and can happen for a number of reasons, including: • The system scope can expand past its initial concept during the development phase. This can be due to last-minute changes in the application, feature creep, or not accurately predicting the memory needs of the application. The options are to either upgrade with a pin-compatible microcontroller that has more Flash program memory, or add additional external Flash program memory which can delay the project if the development is already advanced. • Future firmware upgrades in the field can require more Flash program memory than is available on the microcontroller already in the system board. In this situation the options are limited: either replace the systems in the field with ones containing more Flash program memory or cancel the upgrade. • The system product family development might require a new product that needs more Flash program memory than is already available for the pin-compatible microcontroller family. The options are to redesign the system using a new microcontroller family or add external Flash program memory.
Clearly, it is important for a developer to anticipate the needs of present and future systems for this memory expansion, and plan for it. If there’s a possibility the project will need external Flash program memory, the developer should lay out a place for future expansion of the pc board. While the Flash memory chip does not need to be populated on the board, it’s better to be safe and have the space already laid out. The traditional way of expanding Flash program memory has been to use a parallel Flash interface with address and data lines. However, even the most efficient use of parallel Flash memory that does not sacrifice speed can use 16 bits of address, 16 bits of data, and four or more control signals. This requires 36 or more microcontroller pins. Along with being an inefficient use of a microcontroller’s resources, this limits the microcontroller selection to devices with an external bus, which increases the microcontroller pin count. An external parallel bus also consumes significant pc board space, while the high speed address and data bus increase the possibility of electromagnetic interference (EMI). SPI XIP CODE EXECUTION A more effective option is to use an external Flash program memory device that supports an SPI XiP interface. An SPI XiP interface can use only six pins to interface to the host microcontroller. Electronica Azi International | 3/2019
DESIGN SOLUTIONS » Expand Microcontroller Program Memory
Unlike a conventional SPI interface, the memory on the external Flash memory device is not directly accessed with an SPI firmware driver, but is mapped in the microcontroller’s program memory. A good example of a serial Flash memory device designed to interface using an SPI XiP interface is the AT25SL321-UUE-T from Adesto Technologies (Figure 1). This is a 32 megabit (Mbit) Flash memory that supports single, dual, and quad SPI modes. It supports an SPI clock of 104 megahertz (MHz), which in dual SPI mode provides an equivalent clock rate of 266 MHz, and in quad SPI mode an equivalent clock rate of 532 MHz.
Figure 1 The Adesto AT25SL321 is a 32 Mbit Flash memory that supports single, dual, and quad SPI modes. It provides 32 Mbits of Flash memory in an 8-pin SOIC, DFN8, or TSSOP8 package. (Image source: Adesto Technologies) Along with the 32 Mbits of Flash, the device has status registers to configure the device. Reading from the status registers can tell firmware if the device has a write or erase operation in progress. Writing to status registers allows blocks of Flash memory to be write protected. The Adesto AT25SL321 also has 4 kilobits (Kbits) of one-time programmable (OTP) memory that can be used to store security information such as a unique serial number. It comes in an 8-pin SOIC, DFN8, or TSSOP8 package. Like all serial memory devices that support SPI XiP, the Adesto AT25SL321 is configured using an instruction set specific to Adesto devices. The instruction set consists of 38 commands that are used by the host microcontroller to control the serial Flash. An SPI XiP peripheral on a host microcontroller will include a programmable state machine that is initialized on microcontroller power-up with the instrucwww.international.electronica-azi.ro
tion set of the target serial Flash. Once initialized, the operation of the SPI peripheral is transparent to firmware executing code in the memory mapped SPI XiP region. For example, if the host microcontroller firmware reads data from the memory mapped region, the SPI XiP that is configured with the Adesto instruction set sends a Read Data instruction code followed by a 24-bit byte address to the Adesto serial memory. The Adesto serial memory then sends the memory contents to the host microcontroller one byte at a time. To the firmware this appears as a normal read from memory. Besides an SPI clock, data, and chip select pins, the Adesto AT25SL321 has two additional pins for enhanced in-system functionality. WP\ is an active-low write protect pin that prevents writing to the status register to write protect blocks of code. The microcontroller can use this pin to prevent low priority tasks from making unauthorized changes. HOLD\ is used to pause a data transfer in progress. This can be useful if the microcontroller receives a high priority interrupt signal while a data transfer to the memory is in progress and it needs to be paused until the interrupt is serviced.
The Adesto AT25SL321 32 Mbit Flash device supports four modes of operation: • Standard SPI operation: The Flash memory is accessed like a standard SPI memory device with SPI clock (SCLK), active-low chip select (CS\), serial input (SI) data and serial output (SO) data. Standard SPI bus modes 0 and 3 are supported. • Dual SPI operation: This provides twice the data rate of standard SPI operation by using SI and SO as bidirectional data pins, designated IO0 and IO1. • Quad SPI operation: This provides four times the data rate of standard SPI operation. Besides IO0 and IO1, WP\ and HOLD\ are used as bidirectional data pins, IO2 and IO3. In quad SPI operation, WP\ and HOLD\ features are not available. • QPI operation: This is only used for SPI XiP operation. While standard, dual, and quad SPI modes all support sending commands to the SPI memory using only the IO0 pin, QPI operation supports sending commands using the four IO[0:3] pins, significantly improving SPI XiP performance.
Figure 2 The Microchip ATSAMD51J20A has a full set of peripherals, including an SPI XiP serial interface, ADC, DAC, and support for data encryption. (Image source: Microchip technology) 9
MICROCONTROLLERS
If the Adesto AT25SL321’s 32 Mbits are not sufficient, Adesto also offers the 64 Mbit AT25QL641-UUE-T. The two devices are pin compatible so the AT25QL641 can be a drop-in replacement. Besides having more memory, the only difference between the two devices is that the AT25QL641 is set to QPI operation by default on power-up. This
Bus (AHB) program memory space. To protect data in the serial Flash, the ATSAMD51J20A SIP XiP supports transparent scrambling of data written to external SPI memory and unscrambling of data read from external SPI memory. This can help prevent unauthorized firmware copying and system pirating.
matically set by the SPI XiP peripheral to the address being executed by firmware in the memory mapped AHB memory space range 0x0400 0000 to 0x0500 0000. 3. The Instruction Frame Register configures the SPI XiP for the instruction frame format specific to the external memory device being used. This includes selecting the address length of 24 or 32 bits, enabling double-data rate (DDR), whether continuous read mode is supported, and the opcode length. The rest of the Microchip SPI XiP interface is easily configured using the Microchip SPI drivers.
Figure 3 The Microchip ATSAMD51J20A 32-bit microcontroller has a QSPI peripheral that supports an SPI XiP serial port. This can interface easily to the Adesto AT25SL321 serial Flash using only six pins. (Image source: Digi-Key Electronics) reduces the setup time for the device in high performance systems. Both devices draw only 5 milliamps (mA) during a memory read cycle. Both Adesto memory devices operate off a single 1.7 to 2.0 volt rail and can interface to any voltage compatible microcontroller that has an SPI XiP interface. For the host microcontroller, Microchip Technology has SPI XiP interfaces on its ATSAMD51 series, including the 120 MHz Arm® Cortex®-M4F-based ATSAMD51J20AUUT microcontroller. This device has 1 Mbyte of Flash and 256 kilobytes (Kbytes) of RAM. It has a full range of peripherals including an analog-to-digital converter (ADC), digital-to-analog converter (DAC), USB port, and I2S. It also has a public key encryption peripheral and a true random number generator (TRNG) for security functions. To connect to external Flash memory, developers can use the ATSAMD51J20A’s QSPI peripheral that supports SPI XiP. This allows code to be executed directly from the Adesto Flash memory. The ATSAMD51J20A maps the Adesto Flash into Arm’s Advanced High-Performance 10
USING THE MICROCHIP ATSAMD51J20A WITH AN ADESTO SERIAL FLASH MEMORY DEVICE The Microchip ATSAMD51J20A SPI XiP peripheral has three registers used to send commands to an external serial XiP Flash. Since the serial Flash XiP memory devices from different suppliers use different instruction codes, these registers must be configured as follows by the developer for the specific memory supplier used: 1. The Instruction Code Register contains the instruction used to access the serial Flash. For an Adesto Flash memory device operating in quad SPI mode, this register contains a Fast Read Quad Output instruction 0x6B if firmware is executing code out of the memory mapped XiP region. This register must be changed to the appropriate instruction code if a write, erase, or status register operation is being performed. 2. The Instruction Address Register contains the Flash memory address being accessed in the external serial Flash. When the Microchip ATSAMD51J20A SPI XiP is configured for serial memory mode, this address is auto-
As long as the application firmware on the microcontroller is executing code out of the SPI XiP memory mapped region, the SPI XiP peripheral on the microcontroller does not need to be reconfigured. The Adesto Flash memory also supports a read mode with only the single SI pin with instruction code 0x03. If only dual SPI mode is being used, the instruction code is 0x3B. These codes are written by application firmware to the instruction code register. It is considered good practice to flush any caches associated with memory mapped address space when the instruction code register is changed. When reading or writing to the serial Flash memory status registers, the cache should be flushed, then disabled. This should also be done when writing to the Flash in the memory mapped regions. The cache should be re-enabled once memory read operations are resumed. Because of the high-speed data transfers involved, the serial Flash should be laid out on the pc board as close as possible to the microcontroller SPI XiP port. If that is not possible, then no trace should be longer than 120 millimeters (mm). The clock signal should be at least three times the width of the pc board traces away from other signals to avoid interference. The IO[0:3] bidirectional data signals should all be within 10 mm of each other to avoid skew. CONCLUSION External serial Flash memory devices can provide fast firmware code execution without the complexity and excess board space of parallel Flash chips. This allows for easy program code expansion over time, as well as field updates without redesigning the system board. Digi-Key Electronics www.digikey.com Electronica Azi International | 3/2019
PRODUCT NEWS
New at Bürklin Elektronik
E-T-A`s circuit breaker/switch combination 3120-N offers the best protection against dust, moisture and other penetrating liquids E-T-A offers the optimum solution for all machines or devices that are used in a humid and dirty environment and also require frequent cleaning. E-T-A`s new IP65 rated 3120-N circuit breaker switch with an integrated silicon seal (IP65) and with push-in mounting. Use the benefits related to the traditional PVC covers.
Product Features: • On/Off switcher with integrated overcurrent protection • With innovative accordion-style seal (IP65) • International markings Applications: • Medical equipment • Machine & professional tools • High end garden tools • Construction Equipment Customer`s benefit: • Easy to actuate, even when the user is wearing glove • Protection against dust, moisture and other penetrating liquids • Cost-saving because of longer lifetime Thermal or thermal-magnetic circuit breaker which also serves as ON/OFF switch for devices and machines. Voltage ratings Current ratings Mounting Terminal design
AC 240V, DC 50V 0.1A ... 20A Fast snap-in mounting Blade terminals, screw terminals or push-in terminals
Compliance Approvals Product video https://www.youtube.com/watch?v=WCRoEqbFoE4 Bürklin Elektronik | www.buerklin.com www.international.electronica-azi.ro
11
DATA CONVERTERS
New Innovations in Data Converter ICs
By Mark Patrick Mouser Electronics
While analogue and digital signals may behave quite differently, they often have to work alongside one another in electronic systems. Signals originate in the real world and they need to move back into it for humans to perceive and interact with them. This is where data converters - either analogue to digital converters (ADCs) and digital to analogue converters (DACs) come in, often accompanied signal conditioning to prepare signals for the next stage of processing. Analogue waveforms vary continuously in frequency and amplitude over time, represented by a potentially infinite set of values. The sounds we hear and the words vocalised when we speak are analogue. Images and video are analogue at their source too, translated into vision by the sophisticated analogue sensors that are our eyes. Measuring our heartbeat or tracking our movement both entail capturing analogue signals and 12
The modern world we live in is increasingly swamped in huge amounts of data - made up of signals in both analogue and digital form. Analogue values are characteristic of natural phenomena, such as temperature, light, sound and pressure. Meanwhile, electronic technology relies on the receiving, processing and subsequent transmitting of digital signals. subsequently processing them. In contrast, digital information is represented by discrete time and amplitude quantized signals using digital bits in the binary format. This digital language lends itself to efficient processing and long-term storage of data. It is, as a consequence, used extensively in computing and telecommunications systems. Electronic hardware will always require interfaces that translate signals from the analogue domain into the digital domain, and vice versa. ADCs and DACs are thus fundamental components for engineers to make use of. Consider designing a smart climate control system for a vehicle. Engineering teams faced with this task will need to read multiple analogue temperatures from sensors in different passenger zones throughout the cabin, as well as from external sensors. ADCs will be employed to convert these analogue values into a binary representation - with discrete steps that
can then be processed by the system microcontroller unit (MCU). The MCU will combine this data with commands and settings entered by occupants via a human machine interface (HMI). The analogue temperature values derived from the vehicle occupants (as well as the physical HMI commands) will again be converted to digital signals by an ADC. The digital signal data that has been amassed will then be utilised by the MCU in order to maintain a stable environment. DACs may be used to convert digital signals back to analogue ones to provide feedback to the HMI. The binary code would be completely unintelligible to the vehicle occupants otherwise. Technological progression within the data converter arena Incremental innovations in data conversion over the past few decades have not only enabled performance advances (benefiting Electronica Azi International | 3/2019
DESIGN SOLUTIONS » Multicarrier architecture
everything from cellular communications and medical imaging to consumer audio and video), they have also helped to spawn entirely new applications. Ever rising demand for broadband communications (both wireline and wireless), high performance imaging applications (from medical/scientific imaging to industrial inspection), plus the emergence of AR/VR, facial recognition, etc., have resulted in increased focus on high-speed data conversion. Converter ICs that are capable of handling signal bandwidths beyond 1GHz are becoming more and more commonplace. A range of different mixed signal architectures have been employed to achieve these cutting-edge speeds, each with particular operational advantages. The greater processing power and data throughput enabled by shrinking process technologies, delivering smaller transistors that can switch faster (and at lower power), leads naturally to faster conversion. As a result, broadband signals expand their bandwidths (often to the spectrum limits set by physical laws), imaging systems look to handle more pixels/s - so as to render higher resolution image content faster. As systems are re-architected to take advantage of this extreme processing horsepower, there is an emerging trend toward multi-channel data converters, and even www.international.electronica-azi.ro
software-defined systems. Rather than the conventional approach of doing much of the signal conditioning work in the analogue domain when identifying, filtering and amplifying a radio station signal of interest (before taking the signal into the digital domain), a multicarrier architecture approach might digitise the entire spectrum, and then use digital processing to identify, select and recover signals of interest. This requires more sophisticated circuitry, but offers important advantages, enabling simultaneous recovery of multiple stations. Effectively, a wideband digitiser combined with a powerful processor, plus a data converter with heightened speed and performance, forms a softwaredefined radio that can recover any kind of signal - the signal processing equivalent of virtualisation. Analog Devices (ADI) recently introduced the first in a new line of RF converters designed for elevated bandwidth applications, such as 4G/5G multi-band wireless communications base stations, multi-standard production test systems and defence electronics. Based on 28nm CMOS technology, the AD9213 provides a strong combination of speed, bandwidth and dynamic range. Featuring higher parametric performance, greater Nyquist bandwidth and RF sampling capabilities at higher analogue input frequencies than conventional RF ADCs, it allows digitisation of RF signals up to 7GHz. Designed to enable the next generation of software-defined systems in avionics, instrumentation and communications, it drives greater system integration and reduced power consumption. The AD9213 provides aerospace and defence engineers with the ability to process larger sections of spectrum in electronic surveillance applications, as well as increased resolution and longer range in radar systems.
Figure 1: Texas Instruments’ ADC12DJ3200 ADC. High-density phased-array radar systems, 5G test systems and satellite communications all demand increased data throughput,
ramped-up bandwidth and lower power, while often having PCB footprint constraints too. The wideband ADC12DJ3200 ADC from Texas Instruments delivers an ultra-fast sampling rate of 6.4GSPS at 12-bit resolution. Thanks to its high analogue input frequency range, with direct RF sampling up to 10GHz (covering the L, S and C-bands and extending into the X-band), it enables simplified system architectures and provides enhanced frequency agility, while reducing filter complexity - which in turn saves board space and keeps component count low. For engineers designing continuous monitoring solutions for wearable health and fitness applications, Maxim offers a complete electrocardiogram (ECG) and bio-impedance (BioZ) analogue front-end (AFE). Measuring heart rate, respiration and arrhythmias, the MAX30001 is small and power efficient enough to be incorporated into bio-sensing clothing to monitor and track health metrics 24/7. This clinicalgrade device features high-resolution data converters, delivering 15.9-bits effective number of bits with 3.1μVPP (typical) noise for ECG measurements and 17-bits effective number of bits with 1.1μVPP (typical) noise for BioZ measurements.
Figure 2: Silicon Labs’ Si890x ADC. Designed specifically for the demands of mains line monitoring, Silicon Labs has introduced the industry’s first isolated 10bit ADCs. The devices in the Si890x family employ the company’s patented CMOSbased digital isolation technology. Integrating both ADC and isolation functions provides a much smaller and thinner footprint solution than conventional transformers would be able to. Each ADC input features a 3-channel analogue multiplexer, which enables a single Si890x to monitor up to three different signals (typically AC mains voltage and current, along with the third channel serving as a spare). Mouser Electronics Authorised Distributor www.mouser.com 13
WIRELESS & RGBA
Mix & math Namrata Dalvi from Microchip Technology describes a method for RGBA color mixing using Bluetooth® low energy communications. Controlling the color balance of light-emitting diodes (LEDs) accurately and wirelessly can be achieved using an 8-bit microcontroller and a Bluetooth® 4.1 low energy module to control the red, green, blue, alpha (RGBA) color space. The demonstration board shown in Figure 1 has four LEDs – one each of red, green, blue and amber. The brightness of each of these LEDs is controlled through a pulse-width modulation (PWM) duty cycle. This can be achieved using Microchip’s PIC16F1579 microcontroller, which has four 16-bit PWMs that are used to drive the LEDs. The 16-bit PWMs allow for pre14
cise control over the intensity of each color LED and the mixing of different RGBA brightness levels to create different colors. Using mTouch® capacitive touch sensing technology enables the operation of two capacitive touch sliders. The on-board RN4020 Bluetooth module is used for receiving the PWM values from the Android™ mobile application or desktop program using Bluetooth low energy communication. The board is powered by a 1.5V AAA battery. LIGHTING The light produced by the LEDs varies due to several factors. The brightness, meas-
ured in lumens, will vary for LEDs of different types, and between LEDs of the same type. For color LEDs, the specific color measured by the chromaticity values will differ from one LED to another. Small samples of a particular brand of LEDs were measured to develop a brightness and chromaticity profile. The values were then used as typical values in the hardware design and in the software’s chromaticity calculations. This process is called color tuning. The resistor values were fixed so that each color produced the same number of lumens. The LED series resistors are red 820Ω, blue 400Ω, green 500Ω and amber 500Ω. Electronica Azi International | 3/2019
DESIGN SOLUTIONS Âť Controlling the color balance of light-emitting diodes
Figure 1: RGBA color mixing demonstration board. OPERATING MODES There are two modes of operation: the first is hue saturation value plus white (HSVW) and brightness sliders mode; and the second is chromaticity selector using Bluetooth low energy. The board initially powers-up in mode one. There are two capacitive touch sliders on the board, one for color input and the other for controlling the brightness levels.
The chromaticity selector application GUI consists of the CIE 1931 xy chromaticity chart. The CIE 1931 color space shows a wide range of colors in terms of chromaticity (x) and luminance (y). The color and brightness levels of red, green and blue LEDs mapped onto the CIE color space define a triangle that encompasses all possible shades that can be generated by the output of three devices; this is known as the color gamut.
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The PC GUI and the Android applications used in this mode implement this colormixing algorithm to calculate the PWM duty cycle values necessary to produce the desired color. The chromaticity selector application sends the PWM values over a Bluetooth connection. This connectivity module will be able to communicate with mobile phones and PCs that contain Bluetooth v4.0 [and higher] transceivers. The module is primarily used for receiving duty cycle values from master devices that run the chromaticity selector application. The pin-to-pin configuration between the microcontroller and the BLE module is shown in Figure 3.
If the first slider is touched while in slider mode, the color selected on the slider is output on the LEDs. The selected color is displayed until another input is received. The brightness of a particular color can be controlled with the other slider. For the second mode, the color values (PWM) are selected using an Androidbased mobile application or Windowsbased desktop application. The respective PWM values are then sent to the board via a Bluetooth connection. The application uses the CIE 1931 XY chromaticity chart, see Figure 2. The exact PWM values for the selected color and brightness levels are computed and sent to the RGBA board over the Bluetooth connection. The Bluetooth module on the board then receives the PWM values, which are used by the RGBA board firmware to display the selected color.
triangle between the red, amber and green coordinates. Mixing red, amber and green in different proportions produces the colors within the color gamut in Figure 2.
Figure 2: CIE 1931 color space with RGBA LED color gamut. To obtain a better range of colors, an amber LED has been added. The xy data for the amber LED are mapped onto the CIE 1931 xy color space. This defines another
BLUETOOTH COMMUNICATIONS There are two types of Bluetooth devices – Bluetooth classic and Bluetooth low energy. A Bluetooth low energy device can only communicate with another BLE device or Bluetooth dual-mode device, which has both classic and low energy capabilities. Hence, the master host device must be BLE or Bluetooth dual-mode to communicate with the RN4020 module used on the RGBA board. 15
WIRELESS & RGBA
The module complies with the Bluetooth core v4.1 specification and is controlled by the user through input and output lines and a UART interface. The UART supports ASCII commands to control or configure the module for any requirement based on the application.
store the duty cycle values of all colors. In the wireless communications wrapper class, the interface contains all the methods required by the wireless communications to implement the RGBA application. This interface can be used by any wireless communications method such as Bluetooth low
for devices and the devices are available as a list for the user. The necessary time for the search operation is ten seconds. With the connection state change delegate class, the delegate services the event from the Bluetooth low energy class to determine if the master PICtail card is connected to a remote device or not and displays the current connection state to the user. The constants class stores all the constants required for the application, such as RN4020 module commands and responses, service and characteristic UUIDs and so on.
Figure 3: Interfaces between the Bluetooth low energy module on the left and the microcontroller. APPLICATION SOFTWARE When the board is operating in mode two, the desired LED color is selected from the chromaticity chart in the chromaticity selector application either from the RGBA color mixing desktop or Android application. The red, blue, green and amber PWM duty cycles are calculated by the application. Duty cycle values are passed on to the board by a Bluetooth low energy connection. The desktop application used was developed using Visual Studio C#.NET. The application follows the MVC principle with various classes. The RGBA view controller class acts as the GUI or view manager and as the controller of the application. This class is at the top of the hierarchy responsible for making new objects of classes and performing dependency injection. It also handles all the GUI events and calls appropriate methods. The RGBA calculation class is responsible for finding out if the selected point is either inside the RGB or the RGA triangle or outside of these triangles, and calculates the duty cycle per color for all LEDs. The matrix 3×3 class implements all 3×3 matrix math operations such as inverse, determinant, transpose, co-factor and multiply. The Vector 3 class implements a column vector of size three to be used in matrix maths for the matrix 3×3 class. The RGBA data class is a custom data type to 16
energy and Bluetooth classic. The Bluetooth low energy communications are done using the RN4020 PICtail™ card through RS232 communications by implementing this interface for the RGBA board. The programmer can make a new class to implement wireless communications through built-in Bluetooth low energy libraries in Visual Studio or third party libraries. This interface decouples the implementation of the communications from the actual controller, so if new communications are implemented, the view controller and other classes will not change. The RGBA Bluetooth low energy communications via the RN4020 device class implements the wireless communications wrapper interface for Bluetooth low energy communications with the RGBA board. The PICtail card is used and connected to a PC via the UART or RS232 port. The serial communications are established and commands are sent for Bluetooth low energy communications. The Bluetooth low energy device information class stores the basic information about the remote connectivity device - its name, address and supported server service. This information is used to identify and connect to a remote device. In the search result delegate class, the delegate services the event from the Bluetooth low energy class when it finishes the search
The Java™ application class for the Android operating system follows the MVC principle closely as well, using Android activity classes that are structurally similar to the desktop application. However, the Android application uses the built-in Bluetooth low energy hardware of the Android phone. The Android operating system provides all the necessary libraries for Bluetooth low energy communications with all required events and call backs. The RGBA view activity class is similar to the view controller class on a desktop except for the GUI controls, which are defined in an XML file instead of a class. CONCLUSION This article has shown how a 16-bit PWM allows for precise control over the intensity of each LED. The RGBA LED color mixing board described has slider capacitive touch buttons for color input and brightness control functions. A Bluetooth 4.1 low energy module was used for communications so the user could send PWM values to the RGBA board to output the desired color. The color was selected on a chromaticity selector application on a Windows desktop or on an Android-based phone. Additional resources Original app note: http://ww1.microchip.com/downloads/en/Ap pNotes/00002026A.pdf Microchip Technology www.microchip.com
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CONTEST
Win a Microchip SAM L21 Xplained Pro Evaluation Kit
CONTEST
Win a Microchip SAM R34 Xplained Pro Evaluation Kit
Win a Microchip SAM L21 Xplained Pro Evaluation Kit (ATSAML21-XPRO-B) from Electronica Azi International.
Win a SAM R34 Xplained Pro Evaluation Kit for LoRaWAN development (ATSAMR34-XPRO) from Electronica Azi International.
The SAM L21 Xplained Pro evaluation kit is for evaluating and prototyping with the ultra-low power SAM L21 ARM® Cortex®M0+ based microcontrollers. Microchip SAM L family of microcontrollers are built with innovative picoPower® Technology to deliver best-in-class low power consumption down to 25 μA/MHz in active mode, under 100nA in sleep mode and fast wake-up times of 1.2uS.
A rich set of peripherals, flexibility and ease-of-use combined with Ultra low power consumption make the SAM L21 ARM Cortex-M0+ based microcontroller series ideal for IoT, wireless, and any system that needs large memories and ultra-low power consumption. The SAM L21 is designed for simple and intuitive migration between SAM L devices with identical peripheral modules, compatible code and a linear address map and is compatible with the SAM D family of general-purpose MCUs.
Microchip's SAM R34 Xplained Pro Evaluation Kit is a hardware platform used to evaluate the ATSAMR34 low power LoRa® Sub-GHz SiP, designed to enable long-range wireless connectivity while extending system battery life. The highly integrated LoRa SiP family combines an ultra-lowpower 32-bit microcontroller, sub-GHz RF LoRa transceiver and software stack and is supported by certified reference designs and proven interoperability with major LoRaWAN™ gateway and network providers, significantly simplifying the entire development process with hardware, software and support. The devices also provide the industry’s lowest power consumption in sleep modes, offering extended battery life in remote IoT nodes. Supported by the Atmel Studio integrated development platform, the kit provides easy access to the features of the ATSAMR34 and explains how to integrate the device in a custom design. This FCC, ISED and RED certified board is not only an evaluation platform but also an excellent reference design for developing SAMR34 based LoRa end-node applications. This kit is supported by the Atmel Studio, an integrated development platform, which provides predefined application examples. The kit also provides easy access to various features of the ATSAMR34J18B device and offers additional peripherals to extend the features of the board and ease the development of custom designs.
For your chance to win a Microchip SAM L21 Xplained Pro Evaluation Kit, visit: http://page.microchip.com/Elec-Azi-Int-SAML21.html and enter your details in the online entry form.
For your chance to win a SAM R34 Xplained Pro Evaluation Kit visit: http://page.microchip.com/Elec-Azi-Int-SAM-R34.htm and enter your details in the online entry form.
These MCUs have achieved EEMBC certified ULPMark Score of 410, which is the highest score for an ARM® Cortex®-M23 or ARM® Cortex®- M0+ class device. In addition to ultra-low-power capabilities, these devices feature enhanced Peripheral Touch Controller, chip-level robust security, ARM®TrustZone® Technology, AES, Full Speed USB host and device, Event System and Sleepwalking, 12bit analog, built in opAmps and much more.
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17
POWER MODULES
PASSIVE FILTER DESIGN Concept of Buck Regulators for Ultra-low Noise Applications INTRODUCTION Switched-mode power supply (SMPS) has the advantage of high efficiency compared to traditional Low-dropout (LDO) regulators. Due to its switching nature, a SMPS emits noise at its switching frequency and its harmonics. This article illustrates the procedure of designing filtering to achieve ultra-low output voltage noise of SMPS regulators. Single stage capacitive filter is commonly used for DC-DC converter applications. Low-ESR ceramic capacitors are utilized to meet output voltage ripple specifications. The single stage capacitive filter is sufficient for applications that requires no less than 1-2mV output voltage ripple. For applications such as RF ADC and DAC applications where it is necessary to meet less than 1mV ripple, a second stage LC filter should be used to effectively suppress the switching noise. 18
SINGLE STAGE FILTER DESIGN A synchronous buck converter consists of an
input capacitor CIN, two switches S1 and S2 with their body diodes, an energy storage power inductor L, and output capacitors, COUT. The input source provides energy to the power inductor L and the load when S1 is turned on and S2 is turned off. During this period, the inductor current rises. The energy stored in the inductor is transferred to the output capacitor and load when S2 is on and S1 is off, causing the inductor current to drop. The switching behavior of the buck regulator causes the output voltage to fluctuate. The output capacitors COUT is placed at the output to smooth the output voltage under steady state. The output capacitor reduces the output voltage ripple by providing a low impedance path for the high-frequency voltage components to return to ground. In the subsequent development, it is assumed the buck converter operates under continuous conduction mode (CCM) for output voltage ripple minimization. The inductance of L is designed to meet inductor current ripple requirement. The minimum inductance of L is determined as: LMin=((VIN - VOUT)D)/(IL,p-p fSW)
(1)
Where VIN and VOUT represent the input and output voltage, respectively, D=VOUT/VIN represents the duty ratio, IL,p-p is the peak-to-peak current ripple of the inductor, and fSW represents the switching frequency of the converter. Typically, the peak-to-peak inductor current ripple is selected as 20-40% of the output DC current. The output capacitance is selected to ensure that the output ripple is below the specified peak-to-peak value. For a single stage capacitive filter, an minimum output voltage ripple of 1mV to 2mV can be achieved.
Figure 1: CCM operation of synchronous buck regulator Electronica Azi International | 3/2019
DESIGN SOLUTIONS » Design Concept of Buck Regulators
Figure 2: Typical PCB layout for MPM3833C power module
Under steady state, the net electric charge delivered to the capacitor is zero within one switching period. The capacitor charge of the shaded area in Figure 1 is calculated as: ∆QC = T/4*IL,p-p/2
(2)
Where T is the period of one switching cycle. By definition, the capacitor charge in a given period is also can also be expressed as: ∆QC = C∆VC
(3)
Equating equations (2) and (3), the minimum capacitance to achieve the required output peak-to-peak voltage ripple, VOUT,p-p is determined as: CMin = IL,p-p/(8fSW ∆VC,p-p)
(4)
the switching noise. A typical PCB layout of a MPS power module which integrates optimized inductors to simplify the power converter design is shown in Figure 2. In the PCB layout of MPM3833C, wide copper plane is used for the output power path to minimize power losses. The output capacitors are placed along the output current path. As shown in the figure, as more capacitors are placed on the output plane, the distance from the additional capacitor to the output pin of the power module increases. Consequently, more parasitic inductance is involved in the output capacitor that is further away from the power module. Adding more output capacitance become less and less effective and eventually, the shunt loop is dominant by parasitic inductance.
capacitor. The bypassing capacitor effectively reduces the output ripple to around 3mV at 5V input, 1.2V output, and 2A load. To further reduce the output voltage ripple, 1 additional 22uF output capacitors is place at the output. Since the new capacitor has to be placed further away from the power module, the parasitic inductance involved with the new capacitors is 1nH. The simulated output voltage ripple is shown in Figure 4(a) where the output voltage ripple is reduced to 2mV. Compared to the waveform shown in Figure 3, where one 22uF output capacitor effectively brings down the output voltage ripple to 3mV, the additional one 22uF capacitor is less effective. Figure 4(b) shows the output voltage ripple with one more 22uF capacitor (total of 4×22uF). The last 22uF capacitor involves 1.5nH parasitic inductance in its bypassing loop. As shown in the figure, the output ripple reduction achieved by the additional 22uF capacitor is less than 5% compared to the case where 3×22uF is used. As demonstrated in Figures 3 and 4, the parasitic inductance introduced by the PCB copper/trace will become dominant as more output capacitors are placed on the PCB. Eventually, the benefit of adding more capacitors will be negated by the additional parasitic inductance added in the loop. SECOND STAGE FILTER DESIGN Typically, the shunt output capacitor can effectively reduce the output voltage ripple to 1mV. Beyond this point, a second stage output filter is required to achieve smaller output voltage ripple (sub 1mV voltage ripple can be achieved). Figure 5 illustrates a second stage LC filter which is cascaded to the first stage output capacitors. The second stage filter consist of one filter inductor and its series resistor DCR, a bypassing capacitor branch, and a damping branch. The LC filter works by creating a high impedance to the output.
Ideally, the noise shunt capability can be increased by paralleling more output capacitors. In practical, the output capacitors are laterally placed on a PCB. Adding more output capacitors on a PCB would introduce additional parasitic inductance and AC resistance to the shunt path and thus reduce the effectiveness of bypassing
To demonstrate the impact of loop parasitic inductance, an MPM3833C with various output capacitors are simulated using Simplis. It is assumed that each additional output capacitor introduces an additional 0.5nH parasitic inductance to the bypassing loop. Figure 3 illustrate the output ripple of the power module with one 22uF
Figure 3: Output voltage ripple of MPM3833C with one 22uF output capacitor
Figure 4: Output voltage ripple of MPM3833C with (a) 4×22uF output capacitors and (b) 5×22uF output capacitors
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19
POWER MODULES
The filtering inductor Lf is resistive at the intended high frequency range and dissipates the noise energy in the form of heat. The inductor combines with additional shunt capacitors to form a low-pass LC filter network. The second stage filter is very effective on reducing the output voltage noise when properly designed. It is crucial to size the component of the second stage LC filter for the intended frequency band. The first step of the design procedure involves choosing the first stage output capacitor such based on Equation (4). 5mV to 10mV output voltage ripple is typical for the first stage design. Usually a 10-22uF capacitor is sufficient. The capacitor COUT of the first stage has to be smaller than the bypassing capacitor C1 of the second stage to ensure system stability. Once the first stage capacitor COUT is determined and the specified output voltage ripple (at given frequency) is given, the required attenuation of the second stage LC filter can be determined as: A0,dB = 20log VO,p-p/V1,p-p
Typically, an inductor with 0.22uH to 1uH inductance can be selected to achieve the required output ripple. The inductor should be selected to have minimal DCR as the serious resistance increases power dissipation and reduces the output voltage regulation. It should be noted that as the DC current increases, the core material of the inductor becomes saturated which reduces the inductance of the inductor. Care should be taken to ensure that the inductance is high enough at the rated DC current. Once the filtering inductor is selected, its DCR can be extracted from the datasheet. The second stage LC filter which is a second order filter provides 40db per decade roll-off after the cutoff frequency. The attenuation at given frequency can be estimated as: A(f) = -40log(f/f0)dB
Using the attenuation calculated in equation (5), the required cut-off frequency is determined as:
(5) f0 = f/10(A /(-40)) 0
Where V1,p-p represents peak to peak voltage ripple at the output capacitor and Vo,pp represents the peak to peak of the output voltage (after the second stage filter). Using phasor analysis, the amplitude of the gain of the LC filter is determined as |H(f)|=1/√([1-(2πf)2*Lf*C1]2+(ωRDC*C1)2 (6) Note that the impedance of the damping branch which consists a large series resistor is much larger than the bypassing branch at switching frequency. Thus the filter shown in Figure 5 is approximated as a second order RLC filter. The cut-off frequency of the filter is determined as f0 = 1/(2π√(Lf*C1))
Figure 5: Second stage LC filter with parallel damping branch 20
(8)
(9)
Subsequently, the required bypassing capacitance C1 is determined as: C1 = 1/(4π2*f02*Lf)
(10)
Ceramic capacitors should be used as the bypassing capacitor for the low ESR and ESL. It should be noted that the capacitance of ceramic capacitors experience significant de-rating at DC bias voltage. Figure 6 illustrates the DC de-rating curve of a Murata 0805 ceramic capacitor which is rated at 6.3V. As shown in the figure, at the full rated DC bias voltage, the capacitance drops to 20% of the nominal value. The bypassing capacitor should be selected at the nominal DC bias voltage to factor in the de-rating.
(7) DAMPING The second stage LC filter may introduce resonance peaking if not properly damped. The resonance between the filtering inductor and bypassing capacitor may amplify the output ripple and create undesired ringing at load transient. Figure 7 shows the output voltage of an underdamped converter system with the second stage LC filter. Initially, the system operates under steady state. At t=200uS, a load transient from 1A to 2A is initiated which causes the output voltage to ring.
Figure 6: Typical ceramic capacitor derating curve at DC bias Figure 7(b) illustrate the output voltage and current under load transient of a overdamped second stage filter. To avoid undesired ringing at load transient, the second stage LC filter resonance must be properly damped. In most designs, the second stage filter will be placed outside of the control loop to avoid control stability issue. Consequently, the damping has to be achieved by passive components (additional damping resistors). The filtering inductor usually include a parasitic DC resistance in series with the inductor. This DCR provides damping to the network. However, to provide enough damping for a series RLC circuit, the series resistance has to satisfy RDC > 2√(Lf/C1). In most cases, the DCR alone cannot provide sufficient damping. To this end, a RC damping network is inserted in parallel with the bypassing capacitors to damp the resonant circuit along with the series DCR resistor. DESIGN EXAMPLE The EVREF0102A is the analog power module developed for ZCU1275 Zynq UltraScale+RFSoC Characterization Kit. The EVREF0102 analog power module provides ultra-low noise power supply for the high speed data converters on the ZCU1275 development kit. The EVREF0102A employs five high efficiency step-down switched-mode power modules with integrated inductors. MPM3833C is a 6V, 3A, ultra-small step down power module and MPM 3683-7 is a 16V, 8A power module. Both power modules feature integrated protection functions including OCP, OVP, UVP, and OTP. Compared to the traditional LDO solution, EVREF0102A can achieve up to 80% efficiency improvement. The EVREF0102A analog power module also achieves ultra-low noise level to meet the specifications of Xilinx high-speed data converter by leveraging the forced continuous conduction mode (CCM) operation and implementing post passive filters. Electronica Azi International | 3/2019
DESIGN SOLUTIONS Âť Design Concept of Buck Regulators
CLC passive filters are utilized for the two most sensitive ADC and DAC rails and capacitive filters are utilized for the rest of power
rails. The design procedure is illustrated on the ADC_AVCC rail where MPM3833C power module is employed to power the rail.
Figure 7: Step response of (a) underdamped LC filter and (b) overdamped LC filter
Figure 8: EVRF0102 Ultra-low noise power supply module
The MPM3833C integrates a 1uH power inductor, the current ripple of the inductor at 5V input and 0.925V output is determined as 0.63A by applying equation (1). Subsequently, the first stage output capacitor is selected based on equation (4) as 22uF to provide 3mV voltage ripple to the second stage filter. The required gain of the second stage LC filter is determined by equation (5) as -30 dB to achieve 120uV output voltage ripple at the switching frequency. Considering the size and current rating availability, a 0.24uH Murata chip inductor DFE201612E-R24 is selected with sufficient current rating. The ADC and DAC rails require ultra-low noise across the frequency range up to 15MHz. To provide attenuation with enough margin, the cut-off frequency of the second stage filter is selected as 25kHz. Finally, the filtering capacitors are selected as 150uF. This design is conservative to provide enough margin. The cut-off frequency is selected to compensate the high-frequency gain increase due to the parasitic inductive impedance involved in the filter loop increases at high-frequency (up to 15MHz). A SP-Cap with 100mOhm ESR is selected as the damping capacitor. Since the series resistor of the SP-Cap is high enough for damping, there is no need to external resistor. The FFT results of the output noise measurement of the EVREF0102A is shown in Figure 9. As shown in the figure, the peak noise at switching frequency is reduced to 14 uV. CONCLUSION The design procedure of an output filter is outlined in this article for a buck regulator to achieve ultra-low output voltage noise. A single stage output capacitor filter is capable of reducing the output voltage ripple to up to 2mV. A second stage LC filter is added to effectively reduce the output voltage ripple to less than 1mV. The design of the second LC filter involves selecting of the filtering inductor, the bypassing capacitor, and the damping branch. A design example is given for the power rail of high-speed ADC converter on Xilinx ZCU 1275 kit. The optimized filter effectively removes the output voltage ripple to satisfy the ultra-low noise requirement of on the ADC/DAC rails. For further information: Gergely Balogh, Field Sales Engineer Phone: +36 30 867 0687 e-mail: gergely.balogh@codico.com
Figure 9: Output noise measurement of the ADC_AVCC rail of EVREF0102 www.international.electronica-azi.ro
CODICO www.codico.com 21
POWER MODULES
Keeping trains moving MEETING NEW TECHNOLOGY DEMANDS A key element of the propulsion system for low speed urban transportation to high speed intercity trains is the traction converter that transforms the power from the power source, whether a catenary or diesel engine, to drive the electric motors. By: Michel Ghilardi, LEM Research & Development Senior Engineer The traction converter consists of a rectifier if connected to an AC power source, or a filter in case of a direct connection to a DC grid, as well as an inverter to drive the motor. The DC link is the connection between the rectifier or the DC grid and the inverter. In order to guarantee a sustainable performance, a constant DC link voltage is needed, regardless of the load. To perform the regulation, it is crucial to have a reliable measurement of the voltage level. A key component to perform this task is the voltage transducer. Trains are required to run in areas with severe environmental conditions, including extremes of temperature, dryness and humidity which means that the traction converters and their components are highly stressed. In addition, the evolution of the technology in power electronics, while bringing significant benefits, also implies that additional constraints are impacting the behaviour of the components.
Figure 2: DVM voltage transducers series from 600 up to 4200 VRMS
Figure 1: The traction drive system 22
Electronica Azi International | 3/2019
DESIGN SOLUTIONS » Traction converter
The main benefit of this evolution for the traction converters stems from the semiconductor industry which, with higher switching frequencies, helps to significantly reduce losses and enables a more compact design. The drawbacks are higher magnetic fields and higher common mode perturbations and voltage transducers are highly impacted by these perturbations. The old technologies used for these devices are no longer suitable for the new, more demanding, environmental conditions and this is why the new DVM transducer, using the proven patented technology from LEM, is the right solution. It has an extremely high immunity to external magnetic fields and a partial discharge level higher than the maximum DC link voltage. With a compact design, a good accuracy, a very low drift in temperature and the ability to withstand high common mode dv/dt perturbations, the DVM is the perfect choice for DC-link voltage measurement. LEM NEW VOLTAGE TRANSDUCER (DVM) LEM has designed a new range of voltage transducers based on DVL technology (successfully launched in 2012). The result is the DVM series voltage transducers that cover nominal voltage measurements from 600 up to 4200 VRMS (covered with 6 references – Figure 2) and are a way to extend the voltage measurement above 2000 VRMS which is the highest nominal voltage measured with the DVL series. To operate, they only need to be connected to the measuring voltage, without inserting additional resistors on the primary side, and a standard DC power supply range of ±13.5 V to ±26.4 V. With a primary voltage higher than zero, the transducer consumes a maximum of 30 mA (maximum internal consumption), plus the output current (typically 50mA at nominal value), when set-up with current output. DVM features a combination of all the advantages of previous LEM products and fulfilment to all new EMC requirements. This product series has been designed according to IRIS and ISO 9001 standards and differentiates from previous generation with the 4 following performances: • Low consumption of about 30 mA • Frequency bandwidth 12kHz • Safety insulation 12 kV • Very good accuracy in temperature www.international.electronica-azi.ro
HOW DOES IT WORK? Starting from the left of the diagram in Figure 3 at the primary side, where input voltage might typically be ±4.2 kV, the first stage is a voltage divider that reduces the supply down to a few volts, and is able to withstand high dv/dt while having low thermal drift. Then a sigma delta modulator converts the signal from analogue to digital as a 16-bit output. This is followed by a digital encoder producing a single serial signal enabling data to be transmitted via one single, isolated channel. Thereafter, an amplifier feeds the signal to the primary side transformer required to provide the desired galvanic isolation. At the end, the product insulation test voltage is max 12 kV. The transformer therefore needs to withstand such a high test voltage, while at the same time the lifetime of the insulation can be guaranteed. This assurance is only possible if a partial discharge of less than 10 Pico coulombs is ensured when a 5 kV voltage is applied between the primary and secondary. The DVM has been specifically designed to achieve that performance. On the secondary side, the bit-stream is decoded and filtered by a digital filter. Because the primary signal square wave is distorted by the transformer, a Schmitt trigger is used on the secondary side of the transformer to restore it to square wave. This is then fed into a decoder and digital filter;
does not require changes in the design of the transformer, or in the design of the assembly of the circuit boards in the housing. The microcontroller cancels offsets and adjusts the gain by software and then converts the signal from digital to analogue output. The microcontroller transfers data from the digital filter to a 12-bit D/A converter with a transfer time of around 6 μs. The analogue output voltage is then filtered and converted into a current (±75 mA full scale) using a current generator protected against short-circuits. The microcontroller also regulates a DC/DC converter that creates internal secondary regulated supply voltages. The DVM user typically supplies ±24V or ±15V DC voltage, while the DC/DC converter allows supply to the sigma delta converter and the digital encoder at primary side with ±5V and ±3.3V. The additional circuitry is shown as a group at the top of the circuit schematic, with the frequency of the DC to DC converter given by the microcontroller. The last block to the right of the microcontroller is a voltage to current converter for customers who prefer current output, typically 50 mA at nominal voltage, in order to comply with electromagnetic compatibility (EMC) regulations. The lower impedance current output is less prone to interferences from external electromagnetic fields. A voltage output version of 10 V at nominal voltage is also available, as well as a 4 to 20 mA output for unipolar measurements.
Figure 3: DVM technology: Working principle of the insulating digital technology The function of which is to decode the data bit stream into a standard digital value that can be used in digital to analogue converter within the microcontroller. The recovered output signal is completely insulated against the primary (high voltage) and is an exact representation of the primary voltage. The transducer can be easily adapted for different ranges by modifying the gain programmed by the microcontroller. This
MAIN CHARACTERISTICS With a typical accuracy of ±0.5% of VPN at ambient temperature, DVM shows a quite low temperature drift resulting in a typical accuracy of only ±1 % of VPN over its operating temperature range from -40°C to 85°C. Initial offset at 25°C is 50μA max with a maximum possible drift of ±100μA (typical) over the operating temperature range. Linearity is only ±0.1%. 23
POWER MODULES
The DVM transducer’s typical response time (defined at 90% of VPN) against a voltage step at VPN is of 48μs (Max 60μs). As a result of the fast response time, a large bandwidth has been verified at 12 kHz at -3 dB. MECHANICAL AND STANDARDS LEM has designed its new products to be compatible and to outperform the previous generations of LEM voltage transducers (LV 100 families). Important features and functions include 100% compatible in terms of functions and performance, and improved levels of accuracy and temperature stability, thus greatly simplifying retrofits. The DVM series is 100% compatible for the base mounting footprint, but with slight difference in the outline dimensions such as the primary and secondary connection locations. Thanks to a new design, the DVM is smaller in height (30% less) and occupies 25% less overall volume and is 56% lighter! (Figure 4)
limited to 0.5% of VPN with a DVM 4000 and with a short recovery time of less than 50μs, when this can go up to 18% of inaccuracy and 500μs of recovery time with an equivalent LV 100-VOLTAGE in the same conditions of test. Due to the DVM’s low parasitic capacitance, the effect of dynamic common mode is nearly cancelled out (included in accuracy) (Figure 5), this is an important characteristic as new technologies like IGBT and MOSFETs SIC provide higher dv/dt between primary and secondary. The secondary is generally connected to the ground for safety reasons. The primary is the measurement of differential voltage, but voltage can float. The potential change on the primary can cause a perturbation at the secondary and this cannot be filtered otherwise it would reduce the response time, so the parasitic capacitance between primary and secondary has to be reduced to the lowest
Figure 4: Outline DVM vs LV 100-VOLTAGE
The reduction in size does not compromise the DVM’s high immunity against the external surrounding perturbations or against the high voltage variations, thanks to a highly focused internal electronic design applied on the printed circuit as well as for the mechanic design (Figure 5).
Figure 5: DVM 4000 typical common mode behaviour against dv/dt of 6 kV/us (4200 V applied): Only 0.5% of VPN as error generated with a recovery time of less than 50μs. The error resulting in common mode condition, with 6 kV/us and 4200 V applied, is 24
possible within the transducer design. The previous generation of voltage transducers LV 100-VOLTAGE models are based on the Hall effect technology in closed loop mode and use a magnetic circuit, making them more sensitive to external magnetic fields where DVM does not use a magnetic circuit. The DVM allows easy adaptation to input isolator size depending on input voltage, and any kind of connection for the secondary side such as connectors, shielded cables, terminals (threaded studs, M4, M5, inserts, UNC etc.) according to customer specifications. The DVM models have been designed and tested according to latest recognised worldwide standards for traction and Industry applications. The EN 50155 standard “Electronic Equipment used on Rolling stock” in railway applications is the standard of reference for electrical, environmental and mechanical parameters. It guarantees the overall performances of products in railway environments. For Industry, IEC 61800 for drive applications, IEC 62109 for
solar applications, IEC 61010 for safety. As previously mentioned, special attention has been paid to the mechanical design of the DVM in order to ensure a low level of partial discharges at a high voltage rate. The higher the extinction partial discharges voltage (> 5kV) is, the better it is, as no discharge happens during the normal defined function. The partial discharges level is defined at 10 pC. As the voltage rises, some partial disruptive discharges start between 2 points, usually at the opposite potentials in any product. Maintaining the discharge levels will reduce the product insulation over the time and then eventually impede the quality of the product until it fails. These discharges happen at a level called the ignition voltage and are defined as disappearing usually when they reach a level of 10 Pico coulombs when decreasing the applied voltage (extinction voltage). Usually the extinction voltage is always lower than the ignition voltage. To ensure long life products, the goal is of course to have the extinction voltage at a higher level than the normal working voltage rate. Use of the DVM ensures this, thanks to extinction voltage at 5 kV when the product has been defined to measure nominal voltage from 600 to 4200 VRMS. Accelerated tests have been performed to estimate failure rate, including temperature cycles as well as complete characterisation of the product according to the standards. Thanks to an innovative design using the insulation transformer linked to digital technology, the DVM models guarantee insulation and partial discharges levels for high voltage applications up to 5kV peak. Mainly designed for medium and high voltages, DVM transducers are also suitable for any kind of rugged environments, requiring good performance in terms of accuracy, gain, linearity, low initial offset, low thermal drift, etc. Featuring high immunity to external interferences generated by adjacent currents or external perturbations for example and high immunity against high voltage variations, DVM transducers offer excellent reliability. About the author: Michel Ghilardi is a graduate electronic engineer from the University of technology Saint-Etienne in France. He is head of the traction team at LEM R&D having been at LEM since 2001. LEM | www.lem.com Electronica Azi International | 3/2019
PRODUCT NEWS
Microchip gives its most precise atomic clock a performance upgrade Microchip announces, via its Microsemi subsidiary, the MHM-2020 hydrogen maser atomic clock that improves typical long-term stability performance by nearly 10 times over the previous generation MHM-2010. Building on the MHM-2010’s long service life and cost of ownership legacy, the MHM-2020 offers an upgraded user experience with a colour touch panel display and secure network management port.
Danisense partners with National Instruments to provide current transducers for use in power analysis measurement signal conditioning Danisense, the leader in high-accuracy current transducers for demanding applications, has revealed that National Instruments (NI) has selected Danisense products as its preferred current measurement sensor family for use with its RM-26999 4channel power measurements conditioner. The Danisense DS50UB-10V, DS200UB-10V, DS600UB-10V and DS2000UB-10V current transducers features high accuracy, high bandwidth and low phase shift which are key requirements for accurate power measurement.
Hydrogen masers deliver stability by operating on the principle that hydrogen atoms, in the proper environment, emit microwaves at a precise 1420405751 Hertz (Hz) frequency. Phase-locking this extremely small-power and high-purity signal to a very high-performance quartz oscillator delivers a clock output signal with the necessary long-term stability and phase noise to enable precise time keeping. Active hydrogen masers are the most advanced commercially available atomic clocks produced by Microchip, quadrupling the stability of passive hydrogen masers while providing superior short-term stability compared to cesium beam tube atomic clocks. Designed and manufactured in the U.S., the MHM-2020 maser uses a novel drift-compensation feature to significantly improve long-term clock-drift and aging performance, which is critical for metrology and timekeeping applications. This builds on the legacy of the MHM-2010, which set the industry’s expectations for long service life and low cost of ownership. Its improved performance makes the MHM-2020 the preferred choice of national labs that work with Bureau International des Poids et Mesures (BIPM) standards for maintaining Coordinated Universal Time (UTC) worldwide, enabling users to attain <3E-16/day long-term ageing along with improved temperature stability (tempco) and lower magnetic field sensitivity. The maser’s short-term clock stability performance between 1-100 seconds range meets the stringent requirements of Very Long Baseline Interferometry (VLBI) for radio astronomy research such as studying black holes and other applications that require a low noise, precise frequency and timing reference. The MHM-2020 76001-20X active hydrogen maser and upgrade package for users of applicable legacy MHM-2010 masers are both available. The maser can be specified with an optional low phase noise packaging option. Microchip supports the maser with clock maintenance, on-site repair and consulting services, as well as an extended warranty.
National Instruments’ RM-26999 is a rack-mounted, signal conditioning device that connects to simultaneous-sampling multifunction I/O devices for power measurements. It features four voltage input channels with peak voltages up to 2,000 and four current transducer ports for current measurements. The current transducer ports are optimized for flux-gate transducers by providing all the power, communication, and signal lines required for accurate measurements. The RM-26999 can be used with the modular PXI platform, allowing test engineers to synchronize mixed measurements with their power analysis in one unified system. Engineers can use NI’s RM-26999 Getting Started Guide to select the correct components, safely connect hardware, install the necessary software, and acquire the first measurements in a power measurements system.
Microchip Technology | www.microchip.com
Danisense A/S | www.danisense.com National Instruments | www.ni.com
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By combining complex magnetic performance with advanced electronics Danisense provides efficient and precise solutions that match the requirements of worldwide customers in demanding industries.
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Thermal imaging cameras Thermal imaging cameras are handheld electronic devices with an integrated visual display, designed for detecting heat energy.The key component of a thermal camera is a heat sensor attached to a special type of lens, which is then adapted to work alongside standard image-capture technologies. This allows engineers to quickly identify regions of excessive temperature or sources of wasted heat energy, such as
overheating components or potential thermal insulation gaps in building inspection. On a colour thermographic display, warmer components or regions will show up as reds, oranges and yellows, while cooler parts will typically be shown as purples and blues (green usually indicates areas that are roughly at room temperature). Because they measure infrared radiation, and not visible light, thermal cameras are also useful for identifying heat sources in very dark or otherwise obscured environments. HOW THERMAL IMAGING CAMERAS WORK? An infrared, IR or thermal imaging camera works by detecting and measuring the infrared radiation emanating from objects in other words, their heat signature. In order to do so, the camera must first be fitted with a lens that allows IR frequencies
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to pass through, focusing them on to a special sensor array which can, in turn, detect and read them. The sensor array is constructed as a grid of pixels, each of which reacts to the infrared wavelengths hitting it by converting them into an electronic signal. Those signals are then sent to a processor within the main body of the camera, which converts them using algorithms into a colour map of different temperature values. Itâ&#x20AC;&#x2122;s this map which is sent on to be rendered by the display screen. Many types of thermal imaging camera will also include a standard shooting mode that works with the visible light spectrum, much like any other point-and-click digital camera. This allows for easy comparison of two identical shots - one in IR and one in normal mode - to help quickly identify specific problem areas once the user steps out from behind the lens. Electronica Azi International | 3/2019
INSIGHT Âť COMPANIES
USES OF THERMAL IMAGING CAMERAS: INDUSTRIAL INFRARED CAMERAS Many current thermal imaging cameras are certified specifically for industrial use, with various different configurations and manufacturing standards.
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THERMAL IMAGERY FOR BUILDINGS Instruments designed for use in buildings are typically used to detect issues within the fabric of construction, and for problems that may be obscured from view or behind walls.
Applications include checking the effectiveness of insulation, detecting moisture and leaks, testing underfloor heating systems and central heating appliances, and tracking down leaks from ventilation channels.
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THERMAL IMAGING CAMERAS
RS PRO RS700 Thermal Imaging Camera, Temp Range: -20° +150°C, -4° +302°F 80 × 80pixel
FLIR C3 Thermal Imaging Camera with WiFi, Temp Range: -10 → +150°C 640 × 480pixel
RS Stock # 136-5667
RS Stock # 180-8514
RS Pro thermal Imaging camera is an easy to use thermal camera for fast and efficient thermal imaging using infrared technology. Ideal for electrical and construction in both work and inspections, this thermal camera can detect leaks in pipes, and provides data about a buildings energy efficiency and any defects.
Mfr. Part # C3+MR40
The FLIR C3 thermal camera is designed to assist with building inspections, facilities maintenance, HVAC, or electrical repair. This slim camera fits easily into users pockets making it a fully portable thermal imaging device. Its integrated touch-screen is user friendly, allowing fast and reliable access to finding hidden problems, documenting repairs, and sharing images over Wi-Fi. Featuring a tough rubber exterior and reinforced buttons this infrared camera is extremely durable in harsh environments.
Combining all the important features for thermographic measurement at an affordable price, it also features automatic hot/cold detection. With a built-in digital camera it also allows video and sound recording, USB data transfers for Live video and Wifi for data to mobile devices. The RS700 is safe, accurate, quiet, fast, reliable and robust enough to withstand tough daily use. Thermal images are essential for identifying corroded connections, defects in electrical equipment, overheated motors and potential fire hazards. Included with this article are an adaptor, battery, Micro SD 8GB card, USB cable, USB OTG cable, warranty card, PC software installation CD and a carrying case. Features and Benefits: • Display: 2.8" LCD, 240 × 320 pixels • IR Resolution: 80 × 80 pixels • Image Frequency: 50 Hz • Battery Operating Time: Approx. 4 hours • Integrated LED Light • Built-in lens cover Supplied with: Thermal Imager, Lens, Li-ion battery, Adaptor, Micro SD 8 GB card, USB cable, USB OTG (On The Go) cable, PC software Installation CD, Carrying case
Author: Bogdan Grămescu https://ro.rsdelivers.com 28
Features and Benefits: • IR Resolution 80 × 60 • Digital camera 640 × 480 pixel • 3" colour display 320 × 240 pixels • Image mode: Thermal, visual, MSX®, Picture-in-Picture • Operating temperature –10°C to 50°C (14°F to 122°F) • Vibration and red LED alarms alert users to the presence of voltage in noisy areas • Versatile high/low sensitivity modes detect voltage on industrial equipment and low-voltage installations • Powerful LED worklight always at the ready to illuminate poorly lit locations • Inspection light at the probe tip facilitates testing in dark areas
Aurocon COMPEC authorised distributor for RS Components Electronica Azi International | 3/2019
Leuze: Sensor solutions for AGV Typical application solutions for automatic high-lift trucks, platform vehicles and tractor vehicles Automated guided vehicles (AGV) must transport material or goods from A to B quickly, safely and autonomously. Depending on the application and type of material to be transported, an automatic high-lift truck, a platform vehicle or a tractor vehicle may be best suited. An AGV is controlled via optical guidance, grid navigation or so-called natural navigation. Our sensor solutions also guarantee the precise storage and retrieval of pallets, safe transport even with speed changes as well as vibrationfree transfer of the transport material. The portfolio ranges from cost-optimized sensors for detection to high-resolution navigation and safety solutions.
Safeguarding the transportation path with natural navigation An AGV always travels a predefined path in both directions. To orient itself in the surroundings during navigation without the use of reflectors and to safeguard the transportation path, the surroundings must be scanned with millimeter accuracy. Solution: The RSL 400 safety laser scanner is an area scanner that scans its surroundings with a resolution of 0.1°. A very accurate map of the surroundings is thereby generated for the navigation. With up to 100 switchable protective fields, the safety area of the AGV can be adapted to the respective requirements at any time.
Automatic high-lift truck The automatic high-lift truck is frequently used in highbay warehouses, where it serves as a free-moving highbay storage device.
Position detection of transport material For safe transport, it is essential to check whether the pallet or the transport material was correctly picked up by the vehicle. Solution: With the HRT 25B sensor, up to two switching points can be taught in. The time-offlight technology used here helps to set the switching points for the required distances nearly independently of material and color.
Vertical positioning of the load receptacle It is important that the load receptacle always be positioned at the correct height. Only in this way is it guaranteed that the pallet is safely stored and retrieved. Solution: The AMS 300i sensor delivers measurement data every 2 ms with an absolute accuracy of Âą2 mm. This measurement data can be transferred to the control via a wide range of interfaces. Pallet and rack detection From moving in to picking up the pallet with the load receptacle to placement of the pallet in the warehouse: the vehicle must always detect whether the path is free. The detection of the pallet itself as well as the edge of the shelf rack is also essential. Solution: With the sensors of the 3 series, very precise switching points can be defined independent of material by means of which the pallet and shelf rack can be reliably detected. With up to two digital switching outputs, solutions to these different applications can be found with just one sensor. 30
Integration of safety sensors All safety functions used on the vehicle must be logically linked to one another. One example is the changeover of the protective fields of a safety laser scanner depending on the safely monitored travel speed. Solution: With the configurable safety controls of the MSI 400 series, safety sensors and functions can be efficiently integrated. Though just 45 mm wide, there are 24 inputs/outputs available in the base module. These support the connection of incremental sensors for safe speed monitoring according to EN 61800-5-2 (available soon). End positioning of load receptacle The position of the load receptacle must always be ensured. It should, for example, be in a defined position when changing from slow to fast speed. Solution: Electronica Azi International | 3/2019
The IS 212 inductive switch with M12 external thread detects the position of the load receptacle. Large operating ranges – and a small size – save space and reduce costs here. Pass-under and platform vehicles In semi-automatic production areas such as semiconductor or display production, this type of AGV is used as a more flexible alternative to permanently installed conveyor systems. Grid navigation To find a predefined path, an AGV must always know exactly where it is, regardless of whether it is moving slowly or at high speed. Solution: A simple and reliable solution is grid navigation. The DCR 200i code reader detects 2D-codes that are affixed to the floor in a defined grid even during fast movements. In doing so, the DCR 200i determines the code information and the angle of rotation. Fine positioning To ensure error-free transfer of the transport material, the vehicle must be positioned at the transfer station with millimeter accuracy. Solution: The camera-based IPS 200i sensor determines its position relative to a marker – such as a through hole in the material – with millimeter accuracy. The sensor transfers its absolute measurement values to the control via the interface in millisecond intervals. Presence control of transport material There must be no errors when loading the transport material. It is therefore important to accurately determine its position after every loading and unloading operation. Solution: The compact retro-reflective photoelectric sensors of the 5 series precisely determine the position of the transport material. In addition, technologies such as A2LS make the sensors insensiwww.international.electronica-azi.ro
tive to ambient light. And the highly visible light spot makes the products very easy to adjust. Conveyor control The loading and unloading operation should be activated as easily and efficiently as possible. Often, just one signal suffices here. Solution: The command for activating or deactivating the conveyor is transferred easily, contact-free and economically between vehicle and conveyor system with a 3 series throughbeam photoelectric sensor. The photoelectric sensors can be aligned quickly thanks to their clearly visible indicator LEDs with all-round visibility. Insensitive to ambient light, they function reliably stable. Tractor vehicle Tractor vehicles are often used if material needs to be delivered on belts. For example, in the automotive industry or in the production of white goods. Optical guidance An AGV must move safely and efficiently through its surroundings. Often, however, expansive production and storage areas pose a challenge. Moreover, many sensors are unsuitable for integration in flat vehicles due to their dimensions. Solution: One simple possibility is optical guidance. The vehicle follows a highcontrast track on the floor that helps the sensor in the vehicle determine its position. The OGS 600 compact sensor is available in models with different detection widths and interfaces. Its minimum distance from the floor is just 10 mm. Safeguarding the transportation path To safeguard the transportation path of an AGV, a defined area in front of the vehicle must be checked and the vehicle safely stopped in the event of danger. Solution: The RSL 400 safety laser scanner reliably monitors an area of 8.25 m in a scanning angle of 270°. Due to the possibility of switching the protective fields, the protective field size can be dynamically adapted to the speed. www.oboyle.ro 31
FUJIFILM UVSCALE: Visual verification of ultraviolet light amount distribution Ultraviolet light measurement film enables anyone to measure ultraviolet light amount distribution easily by just cutting to size and inserting as required. This Fujifilm technology finds wide range of applications and measurement techniques. UV light distribution analysis system Management by converting colors into numeric values with analysis systems. In this system, exclusive analysis software is used along with a special scanner. The system makes it possible to scan the color of UVSCALE, convert it into UV light values, analyze UV light distribution, and save them. The separation accuracy of the densities can be improved so sections that cannot be judged visually can be analyzed. Managing numerical data can have the following advantages:Internal inspection standards can be set. Analysis results can be shared. Digitizing data makes it possible to compare it to past data. Structure and principle Structure One side of the base film has a UV light sensitive layer and the opposite side has a white layer. The light sensitive layer changes color according to the amount of UV light it receives, so the amount of light distributed on the exposed surface can be easily seen by observing the light sensitive layer and white layer when they are attached to the base. Principle The color-forming material in the microcapsules reacts with the UV light and changes color. Standard color chart The figure on the right represents color characteristics generated by a high-pressure mercury lamp. However, please note that these color characteristics are values generated by using Fujifilm light sources and devices, so there may be differences in color density for a given amount of light due to differences and variations in individual lamps or the environment. Advantages of visual checks Referring to standard color charts makes it possible to visually judge accumulated light values in an easy way. Providing color samples can significantly reduce the time necessary for checking the amount of UV light when starting work and switching objects to be exposed. How to use UVSCALE 1. After cutting UVSCALE to the required shape (length), place it on the location that you want to measure. 2. Operate the equipment or device, and expose UVSCALE to UV light.*The side of the UVSCALE with the matte surface should be exposed. 3. UVSCALE changes color in accordance with the amount of UV light. 32
Electronica Azi International | 3/2019
4. Remove the UVSCALE, and determine the distribution of UV light by observing the color distribution.*Use the matte side for observing.
5. Set UVSCALE on the special scanner and scan the color sample.
6. Analyze it on a PC with the exclusive software installed.
Correction function Measurement function Entering a correction value can correct differences in light amount values caused by differences in illuminometers, temperature, and other measurement conditions to obtain an appropriate value. Furthermore, the obtained data can be converted into numerical values, and the measurement data of the entire area or specified parts can be displayed in rectangular or circular form. www.oboyle.ro
Sensor Instruments: Welding Seam Detection with Edge Detectors For the detection of welding seams, contrast or color sensors would seem to be the proper solution, because in most cases the welding seam optically shows a clear difference from the surrounding product surface. In everyday practice, however, it turns out that these methods involve frequent readjustment and reparameterization. On the one hand this is due to the varying, product-dependent distance of the object surface from the sensor, and on the other hand to the highly alternating appearance of the respective welding seam with respect to color and contrast. Both methods, however, seem to be completely unsuited for printed objects, especially if a color or contrast similar to the welding seam is already contained in the printed material. So-called eddy current sensors offer a completely different approach, because the metallurgical structure of the object in the welding seam differs from the remaining metal sheet. This method, however, requires recalibration of the measuring equipment when the product changes with respect to sheet thickness, metal type, welding method, and distance of the object from the sensor. Edge detectors might offer an alternative here. All that is required is the existence of an edge, which by nature should be the case with a welding seam (with the exception of polished welding seams). The sensors of the RED series operate with the principle of edge detection. A laser spot or a focused laser line is projected onto the object surface. The laser spot is detected by two photodetectors that are integrated in the laser sensor. These two detectors are positioned in such a way that the detector that is close to the laser transmitter receives more light when there is an edge, whereas for the detector that is opposite to the laser transmitter the laser light beam so to speak is blocked. The sensor's integrated controller with its software then compares the signals of the two detectors and provides a result that is independent of the intensity. The outstanding feature here is that smallest edges, even on printed objects, are reliably detected by the sensor (RED-110-L) in a distance range from 90mm to 130mm. The advantages of edge detection! www.oboyle.ro www.international.electronica-azi.ro
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INXPECT: INDUSTRIAL SAFETY - LBK System Volumetric Linear Safety Barrier The LBK System has been designed for use around hazardous machinery and robot automated areas providing perimeter or area access detection. An affordable SIL2 Volumetric Linear Safety Barrier, the LBK System is built around FMCW radar smart sensors, with dynamically configurable presence sensing areas (warning +danger). Suited for application where smoke, dust, shavings, machining waste, splashes, usually lead optical detectors to generate false alarm, the LBK System can be easily configured through the provided PC Software application. The LBK System is proudly engineered, designed and made in Italy by Inxpect.
Immunity to visible objects like smoke, dust, shavings, machining waste, splashes A perfect alignment between sensors is not required Configuration, e.g. the depth of the warning and danger areas, can be made quickly and easily through the provided PC application The system can detect the presence of humans and can give pre-alarms in order to avoid the sudden stop of the machinery The system detects which part of the danger area has been entered: different actions can be configured depending on the accessed zone Operator protection, robust to dust and smoke The use of safety devices for personnel, workplace protection and in machine safety can vary depending on the individual manufacturing markets. However, there are plenty of industrial applications that may require safety barriers where traditional optical or pressuresensitivebased solutions cannot be applied.
A new Safety Barrier technology that offers superior safety protection without compromising productivity and efficiency, even in harsh industrial environments The LBK System provides an Industrial Safety Barrier , and is based on the LBK-S01, an innovative radar-based motion sensor device that, together with the appropriate LBK Control unit, ensures that automated machines or robots enter in safe mode when operators enter or are present in a dangerous area. The LBK System consists of at least an LBK-S01 smart motion sensor that operates in combination with an LBK-C22 Control unit, realizing an active protective system, SIL2, in accordance with IEC 61508. Main features: ■ Two dynamically configurable depths: warning and danger ■ Configurable EDM and Restart Interlock I/O ■ Configurable non-safe relay output for Pre-alarm, Muting or Ready condition signalling ■ No additional mounting hardware required 34
Electronica Azi International | 3/2019
ture and to Inxpect ’s proprietary system design, LBK-S01 can compute in real time the distance of the moving personnel reaching unsafe areas. The LBK-S01 is undisturbed by smoke, dust, shavings, machining waste, splashes, resulting in a dramatic reduction of false alarms, and significantly increasing the efficiency and productivity of the plant without compromising safety.
Where light curtains, laser barriers, or safety mats fail, the LBK Safety Linear Barrier system is the solution.
The Inxpect LBK-C22 is the Safety barrier control unit used to monitor up to 6 LBK-S01 smart detectors. Intervention of any single detector results in deactivation of the safety output.
The LBK-C22 control unit can be configured through a provided application, connecting a PC with a USB cable. Sensibility adjustment, depth of the warning and danger areas can be easily configured as well as auxiliary output relay functions. The configuration parameters also allow to set the system in order to work with an external EDM and manage Muting requests or Restart Interlock functions. The Inxpect LBK-S01 smart motion detectors are based on FMCW radar technology, a proven technique that guarantees best in class performance at detecting and tracking motion. Unlike traditional motion sensors based on infrared, laser or microwaves, thanks to its advanced architecwww.international.electronica-azi.ro
Programmable Field of View Each LBK-S01 sensor in the LBK System can be field-programmed, independently from the others, to cover either a Wide or a Narrow Field of View. The actual field of vision of the sensor depends on installation height and tilt.
Fields of application ■ Robot automated areas ■ Food and beverage industry ■ Hazardous machinery ■ Material handling equipment ■ Packaging machinery ■ Special machine construction www.oboyle.ro 35
Leuze: Precise measurement, positioning, quality assurance of objects In highly automated systems in intralogistics and production, precise monitoring and measurement of distances is essential for smooth running in daily operation. Distance sensors are used for this purpose in, for example, stack height measurements, quality assurance in assembly lines or for positioning of vehicles. We offer a comprehensive product range of optical distance sensors that enables pinpoint measurement, positioning and quality assurance of any objects over long and short distances. Our sensors are based on various measurement operating principles (triangulation measurement, propagation time measurement, phase measurement). These enable both the reproducible measurement of distances in the range of tenths of a millimeter as well as over larger distances in excess of 60 meters. The measurement data can be transferred with IO-Link and evaluated with software in the machine. Based on the current values, production processes can be constantly adapted and optimized. Quality assurance
Stack height measurement
Positioning
Requirement: During assembly processes, the completeness or alignment of individual components must be ensured. To do this, the reference points must be defined and checked. Solution: Due to their high resolution at close range, the ODSL 8 and ODS 9 sensors are suitable for checking reference points. Robust plastic and metal housings are available.
Requirement: With machining processes, the raw material must be fed into the machine without interruption. To ensure this, the stack height on the load carrier must be constantly detected. Solution: The ODS 9 sensors with ODSL 96 with different resolutions and ranges make it possible to measure the height of differently stacked objects.
Requirement: For the positioning of vehicles and side-tracking skates, their distance to a specified reference point must be measured. Solution: Thanks to their large operating ranges of up to 65 meters and a focused laser, the ODSL 30 and ODS 10 sensors are suitable for positioning. Models with and without reflector are available. www.oboyle.ro
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Electronica Azi International | 3/2019
Contrinex: Transparent-object sensors with patented UV technology detect presence of clear plastic sheet during thermoforming During automated packaging, high-speed thermoforming lines produce transparent plastic blister- rays from continuous reel-stock material. Transparent-object sensors with patented UV technology detect the presence of the transparent plastic sheet as it is unwound, ensuring the material is correctly tensioned as it enters the loading station. False detection is avoided, ensuring reliable operation with little or no downtime. Ecolab-certified, these sensors are also suitable for the packaging of medical products.
Customer value ■ UV sensors ensure reliable detection of transparent plastic targets ■ Safe detection of the thinnest transparent materials ■ Maximum operating reserve owing to high absorption
factor of UV light by transparent plastics ■ Elimination of multiple switching on a single target ■ Reliable operation without the need for manual intervention ■ Very low sensitivity to dust, liquid droplets and splashes ■ Wide operating range accommodates full range of machine geometries ■ Simple one- or two-step teach procedure optimizes initial sensor set-up ■ Sensitivity parameters are retrieved or updated remotely via IO-Link ■ Stability alarm highlights reduced sensitivity, avoiding unplanned stoppages Specific product advantages ■ Ultraviolet reflex photoelectric sensors for transparent object detection ■ Very low sensitivity to target shape ■ IO-Link serial-connection protocol enabled on PNP versions at no additional cost ■ Pre-taught sensitivity parameters stored on inbuilt sensor memory ■ Remote sensitivity retrieval or update via IO-Link ■ Highly tolerant of contamination by dust, liquid droplets or splashes ■ Robust, Ecolab approved sensors with IP67-rated miniature plastic housings www.oboyle.ro
Sensor Instruments: Choose the Right Side 95% of all the industrially produced flat glass today is made using the float glass process. In this process, molten glass is continuously fed into a bath of molten tin. Due to its lower specific weight the molten glass floats on the smooth tin surface, and on a long tin bath forms a uniformly thick and extremely smooth film. The glass side that faces the molten tin is slightly contaminated with tin, which has corresponding effects on subsequent float glass processing steps such as coating of the glass surface. For the further processing of float glass it is therefore important that the surface that is contaminated by the tin bath can be distinguished from the so-called fire side (fire polishing, during float glass production the glass side facing away from the molten tin is heated). According to experience the float glass surface facing the tin bath shows a clearly reduced optical direct reflection in the UVC wavelength range. With a contrast sensor of type SPECTRO-1-FIOUVC/UVC and quartz-glass reflective fibre optics R-S-A3.0-(3.0)-600-22°- UV the tin side due to its reduced light reflection without any problems can be distinguished from the fire side, irrespective of whether the float glass is tinted, highly tinted, or not colored at all. The fibre optics frontend is vertically directed onto the respective glass surface at a distance of 5mm. Extraneous light influences are prevented by means of pulsed light and correspondingly adapted optical filters. Due to its non-contacting measuring method the system also is suitable for inline applications. For offline use a suitable fibre optics mount is available. www.oboyle.ro www.international.electronica-azi.ro
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PRODUCT NEWS
New environmental sensor technology: photoacoustic spectroscopy (PAS) miniaturizes CO2 sensor XENSIV™ PAS210 City dwellers often spend a large amount of their time indoors, either in an office, at school, or simply at home. Urbanized spaces, however, tend to trap and develop bad air quality as they get more insulated for energy efficiency purposes. The concentration of CO2 is an indicator for bad air quality. Today´s market solutions for monitoring this odorless and colorless gas are bulky and costly or simply not good enough for a widespread adoption. Infineon Technologies AG has developed a disruptive CO2 sensor technology based on the photoacoustic spectroscopy (PAS). XENSIV™ PAS210 makes use of this new technology. It implements a high sensitivity MEMS microphone as a detector and enables significant miniaturization of CO2 sensors. For this reason, it is ideal for smart home applications and building automation i.e. demand controlled ventilation, as well as various indoor air quality IoT devices such as air purifiers, thermostats, weather stations, and personal assistants. The sensor helps to improve the indoor air quality in a timely and energy efficient manner. Based on an extensive portfolio of patents around the PAS technology, PAS210 will not only enable high volume and cost sensitive CO2 sensing applications but will also pave the road for the detection of other gases in the future. On a single PCB, the CO2 sensor integrates the photoacoustic transducer including the detector, the infrared source and the optical filter. It also holds a microcontroller for signal processing and algorithms as well as a MOSFET to drive an infrared source. All the components are developed and designed in-house according to Infineon´s high quality standards, leading to the bestin-class price/performance. For instance, XENSIV PAS210 uses the high SNR (Signal-to-Noise Ratio) MEMS microphone XENSIVE IM69D130 as a detector. The sensor thus benefits from Infineon´s long record of accomplishments in acoustic technology and related applications. PAS210 is a real CO2 sensor in an unprecedented small form factor, enabled by the unique PAS detection principle. The sensor saves more than 75 percent space in customer end products compared to commercially available real CO2 sensors. Its direct ppm readings, surface mounting capability and simple design allow for an easy and fast integration in low and high volume applications alike. The integrated microcontroller converts the MEMS microphone output into a ppm reading, which is available either via the serial I²C, UART or PWM interface. XENSIV PAS210 CO2 measurement capabilities cover a range from 0 ppm to 10,000 ppm with an accuracy of ±30 ppm or ±3 percent of the reading. In a pulsed mode, the XENSIV PAS210 CO2 sensor is designed to have a lifetime of ten years. More information is available at www.infineon.com/PAS210. Infineon Technologies | www.infineon.com 38
Nameplate with Venting Function from Schreiner ProTech Smart sensors have become indispensable to modern industrial transportation systems: RFID devices ensure a seamless identification solution in line with Industry 4.0 throughout the entire value creation process. Complete transparency and planning certainty will play an increasingly important role for companies in the future. SICK produces sensors that have to resist challenging target applications with numerous environmental influences such as major temperature fluctuations and the effects of moisture. For efficient venting and marking of such housings, Schreiner ProTech has developed a nameplate that is combined with a pressure compensation seal (PCS).
Temperature fluctuations may result in excess pressure or vacuum in electronic housings. Pressure differences stress the assembly components and their individual elements and may cause damage resulting in the destruction of the electronic system. A pressure compensation seal regulates this pressure by means of its membrane and at the same time provides protection against external influences such as water or dust. In many cases, housings require both protection and marking. However, separate products and process steps for pressure compensation and marking slow down the production process and increase the rate of defects. Reduced qualification requirements due to just one product being applied to the housing are additional benefits. Furthermore, customized inscriptions can be performed at the customer’s site and the size adapted to the customer’s requirements. The label complies with IP 67 (protection against foreign particles, water and contact). System Expertise Membranes are high-tech products requiring professional processing for proper performance. To ensure their reliable application to components, Schreiner ProTech offers an application system that is optimally adapted to self-adhesive pressure compensation seals. Schreiner ProTech | www.schreiner-group.com Electronica Azi International | 3/2019
SAKI Corporation Introduces Ultra-fast, Inline, 2D Bottom-side automated Optical Inspection for PCBs By: Ikumi Sugawara, email: sugawara.ikumi@sakicorp.com, Saki Europe
Featured at NEPCON China and SMTconnect Saki Corporation, an innovator in the field of automated optical and x-ray inspection and measurement equipment, announces the release of its new 2Di-LU1 inline bottom-side automated optical inspection (AOI) system at NEPCON China, Shanghai, China, and SMTconnect, Nuremberg, Germany. Saki’s 2D linescan technology is ultra-fast, capturing the image of an entire 460×500mm printed circuit board assembly (PCBA) and 610×610mm as a carrier size in one pass, in real time, storing the image into memory, and creating inspection data for the entire board. This versatile system automates the bottom-side inspection process, eliminates board flipping and handling, and ensures quality after the potting, dip, wave, and selective soldering processes. The 2Di-LU1 software includes Saki’s proprietary Fujiyama algorithm, which provides complete throughhole joint inspection in a single step. It simultaneously inspects for copper exposure, pin detection, pin-holes, solder fillet abnormalities, missing components, soldering problems, and bridges. Saki’s inspection software has been used for extra component detection of solder balls and foreign objects and through-hole device inspection in the automotive industry for several years and complies with the IPC-A-610 standard. “Incorporating bottom-side AOI into the assembly process increases productivity by reducing the time, costs, labor, and floorspace needed for manual inspection, additional conveyors, or equipment to flip the board,” explained Yoshihiro Akiyama, Chief Technical Officer (CTO), Saki Corporation. “Saki’s system speeds the inspection process, increases throughput, and eliminates extra PCBA handling and the risk of substrate damage.” The platform and construction of the 2Di-LU1 bottom-side AOI system is based on Saki’s rigid, time-tested hardware that ensures very stable machine performance and long hardware life. The system supports L-size PCBs, high clearances, heavy and substrates. Saki will feature its 2D bottom-side AOI system, along with its 3D AOI, SPI, and AXI systems and Saki Self-Programming Software, at NEPCON China, Shanghai, China, in the Saki booth 1J30 and the Fuji booth 1G60, being held April 24-26 and at SMTconnect, Nuremberg, Germany, in Hall 4A133 being held May 7-9. For more information contact Saki at sakicorp@sakicorp.com or sales.us@sakiglobal.com, or visit our website at www.sakicorp.com or www.sakiglobal.com. LTHD Corporation S.R.L. Head Office: Timișoara - ROMÂNIA, 300153, 70 Ardealul Str., lthd@lthd.com, www.lthd.com Tel.: +40 256 201273, +40 356 401266, Fax: +40 256 490813
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LTHD Corporation S.R.L. Head Office: Timișoara - ROMÂNIA, 300153, 70 Ardealul Str., lthd@lthd.com, www.lthd.com Tel.: +40 256 201273, +40 356 401266, Fax: +40 256 490813
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Electronica Azi International | 3/2019