BIG PICTURE

The XR Market in India is Growing across Industries

Gulshan Purswani

Delivery Head at Robert Bosch Engineering and Business Solutions

Why are brands and businesses turning towards XR(Extended Reality) tech? How is XR relevant to businesses, employees and customers - how to decide if you need it? Robert Bosch Engineering and Business Solutions Pvt. Ltd (RBEI), R&D wing of Bosch has been extensively focusing into this advance tech segment. Niloy from BISinfotech gets alongside for an exclusive interview with Gulshan Purswani, Delivery Head at Robert Bosch Engineering and Business Solutions exploring the future, strategies and potential of XR. Lot more interesting insight unveiled below.

QThe potential of Extended Reality (XR) and Robert Bosch Engineering and Business Solutions Pvt. Ltd (RBEI) key focus and offerings?

XR has potential applications across manufacturing, field service and customer experience. We at RBEI are actively working on solutions in all three areas. Our key offerings are in the areas of scalable solutions. With over a decade of successfully delivering XR projects, we are currently focussing on development of frameworks / platforms that will enable us to implement such solutions much more efficiently.

QThe impact of pandemic on enterprises and businesses and how are they looking into a future enabling a DigitalFront experience?

The pandemic has accelerated the adoption of digital front experiences in both manufacturing and customer experience. We have seen instances where earlier an expert would have travelled halfway around the world for a plant / machinery installation but with the lockdowns and travel restrictions, these experts had to adopt remote assist tools in combination with hardware such as HoloLens. Another example is the number of ecommerce websites that have adopted 3D experiences to sell their products online.

QHow can XR help businesses and why should businesses adopt it?

XR can help businesses expand their reach beyond their brick and mortar setup and overcome the current restrictions. The key checkpoint for any business is to find XR cases with a quantifiable ROI. Businesses should find the areas where they struggle the most and XR could solve that problem for them. Decisions such as which device to use, which platform to use, AR or VR, wearables or tablets would come in at a later stage.

QHow RBEI works with enterprises to help them decide the best strategy on XR (AR/VR/Mobile/Browser) based on their business requirements?

RBEI brings its wide technology expertise to the table when working with enterprises. We work closely in consulting and joint development models with our customers and take them through their XR journey. Our typical engagement model involves a discovery phase where we conduct design workshops to identify the pain areas, milestones, success criteria etc. Post this we get into system design and develop phases to working with short checkpoints. We work in Agile model which allows us to make course corrections along the way. The second important part of successful engagement is the right team. We bring UX experts, design experts, architects and core technical teams to ensure that our XR products are well rounded and effective. For example, we recently worked with a customer where high precision AR was required for automotive sales and service experience. This was supposed to be very high quality AR project with realistic paint shades that were overlaid on a physical car with millimeter level accuracy. We worked closely with the customer discussing the pros and cons of different options – wearable vs mobile vs tablets, processing and storage options – device vs cloud, make vs buy options for complex software components and agreed on quick win milestones. At the end, we had a product so realistic that you could easily mistake the content for a real car. We have done projects in training, manufacturing and customer experiences where each one had its unique complexity and technology challenges.

QWhat is the efficacy of novel forms of assessment within XR?

We have been able to demonstrate efficacy of trainings through various approaches to ensure effective recall, muscle memory and therefore transference. For example, one of the most common ways is assessment approach. We run the VR simulations in “Assessment Mode” where the user will be tested on accuracy, speed and handling of failure scenarios. All our trainings come with “Training”, “Assist” and “Assessment” modes. This is commonly used in enterprise setup with structured training and evaluation practices. Another example of checking the efficacy is to evaluate transference. How well is the person able to implement learnings in the real world? This needs more customised approach as the scenarios can differ. Recently, we were able to demonstrate the efficacy of VR trainings for special students where they independently took public transport. Assessments were designed to gradually move them from gamification to real world and therapists and teachers closely working with them evaluated the success of their trainings. We also support integrations with learning management systems (LMS) to provide trends and analytics over a period of time. Identifying the key success criteria and ways to measure them effectively is something we do at the very beginning stages of our projects.

QHow can learning and performance be accurately assessed in XR environments?

There are various methods which we use starting with basic assessment scores to analytics based solutions that will track progress over a period of time.

QThe potential Indian market for XR and your strategies to incorporate it across the market?

The growing smartphone penetration has a lot to contribute here. The XR market in India is growing across the industries of retail, infrastructure, education, healthcare and a lot more. We are looking at enhanced customer experience, advanced-learning methodologies across sectors and we are just at the tip of the opportunity iceberg.

QKey privacy framework, ethical guidelines and immersive technology standards helping this nascent technology be sustainable and viable in the future.

Privacy, responsibility and ethical practices must be baked into the design and development of XR solutions well ahead of implementation. For data protection, regulations such as GDPR, Personal Data Protection Bill 2019 are certainly paths to protect sensitive data. Ecosystems such as IAMAI (Internet and Mobile Association of India) and VRARA (VR AR Association) comprising of business leaders & policy makers would encourage that the standards and security are treated as a priority.

How to design modular DC DC systems, part 4: safety protection systems

Jonathan Siegers

Principal Applications Engineer and Vamshi Domudala, Application Engineer, Vicor Corporation

The previous tutorials in this series detailed the practical design considerations of utilizing power modules for designing power delivery networks (PDNs). Once a designer has chosen appropriate DC-DC modules, designed filters for the input and output of the modules, and provided for the overall stability of the system, the next area of concern is safety. Fuses and transient suppression circuits must be designed into the system to ensure protection from catastrophic failures without making the system unreliable or inefficient.

A well-designed power system needs to be protected; fuses limit thermal damage and isolate faulted systems, and a transient suppression circuit will tame surges and spikes that destabilize the system and endanger the power module.

Fuse requirements and functions

The starting point for fuse selection is the safety agency conditions of acceptability (CofAs) provided in the manufacturer’s DCDC module documentation. Designers must consult the latest available documentation and select the appropriate type of fusing to ensure agency CofAs are met.

Fuses are a critical safety element of the system. They perform two main functions: • Limit the extent of thermal damage caused by overcurrent or a short-circuit event. • Isolate faulted subsystems.

First, thermal damage caused by a serious failure in an unfused system can be extreme: printed circuit boards can be burned to charcoal with every component completely destroyed, depending on the available fault current. Besides preventing fires, fuses also help preserve enough of the system in the event of a fault that failure analysis is possible. Second, fuses perform the role of isolating a faulted subsystem from the total system, preventing unnecessary downtime. In order to ensure fuses adequately perform both functions and to satisfy safety agency requirements, each power module must have its own fuse placed at the input side. In the next figure, a fault at either of the non-isolated point-of-load converters or in the input circuitry associated with it would cause that particular fuse to open while leaving the rest of the system capable of continued operation.

Fuse placements in a power system employing three DC-DC modules; note that each module has its own fuse for protection.

Selecting a fuse

The first and most important parameter to consider when selecting a fuse is the current rating. The current rating must be greater than the maximum continuous operating current of the protected system. In a regulated DC-DC module, the maximum continuous operating current condition occurs at the minimum input voltage and at full-load power. Include an estimation of the module’s operating efficiency under these conditions to more precisely define the maximum continuous operating current.

Fuse manufacturers typically recommend that designers also include a 25 – 50% de-rating when calculating the fuse’s necessary rated current value. This accounts for normal fuse aging, but it also prevents nuisance tripping and frequent fuse replacement.

Once the basic fuse current rating is determined, designers need to consider the environmental conditions under which the system will operate. Fuse manufacturers’ data sheets include a temperature de-rating chart like the one shown in the following figure. Depending on the application and expected ambient environment temperature, it may be necessary to modify the calculation of the required fuse current rating.

Example of a typical fast-acting fuse temperature de-rating chart; notice especially the additional de-rating for operation above 25°C.

Fuse manufacturers represent fuse current ratings at a typical temperature of about 25°C, but an elevated ambient temperature will lower the fuse’s effective current rating. Since the fuse will trip at a lower current when the ambient temperature is above 25°C, it is necessary to use this chart to apply an additional de-rating and raise the current rating of the fuse chosen for the system accordingly. The same recalculation is helpful for lower temperatures: if the environmental ambient temperature is typically below 25°C, select a fuse with a correspondingly lower current rating.

The fuse’s voltage rating is also a safety-critical design choice because it ensures the fuse remains an open circuit when tripped and does not allow for re-striking of an arc that would cause further damage in the system. It is crucial to select a fuse with an appropriate DC voltage rating that corresponds to the maximum withstand voltage the system can tolerate. In other words, the fuse’s voltage rating must meet or exceed the maximum voltage of the application.

Next, consider the maximum interrupt current rating of the fuse or the breaking capacity. This parameter, which must meet or exceed the maximum available short-circuit current of the protected circuit, dictates the maximum fault current that can be interrupted by the fuse during an overload condition at the rated voltage. This rating ensures that the fuse clears the fault from the system during an overcurrent event without experiencing damage to its own packaging. A clearing event that also damages the fuse packaging will likely cause damage to adjacent components on the circuit board and is an unsafe failure mode.

Note that the fuse voltage rating and interrupt current specification may or may not depend on whether the application is for an AC system or a DC system. Carefully read the fuse data sheet specifications to understand the manufacturer’s intended meaning.

Nominal melting I2t

Next, consider the nominal melting I2t rating for the fuse in order to accommodate some expected events that shouldn’t cause the fuse to trip. For example, DC-DC systems typically charge capacitance at start up and, therefore, might experience high peak inrush currents as part of the normal course of operation. These higher peak currents can also occur during externally introduced transients that are within the range of normal expectations for the system.

A fuse’s nominal melting I2t parameter corresponds with the thermal energy necessary to melt the internal fuse element itself. For example, in an application with DC-DC converters, pulse current overloads are a common occurrence and may actually exceed the rated fuse current of the selected component.

To calculate this value and select the appropriate fuse, consider the expected current waveform and its energy in joules. The next figure shows two representative waveform profiles and the pulse I2t of each. This calculation yields the expected energy that the fuse must pass without tripping, which means that the I2t rating of the selected fuse must be above this value.

Representative pulse shapes and I2t equations—sine (left) and lightning (right).

For increased design margin and to reduce the frequency of fuse replacements over the lifetime of the system, a pulse factor that accounts for the number of surge events the fuse must survive should be applied to the calculated I2t value.

Additional fusing considerations

There are other important factors to consider when designing fuses into a power system. Among the most notable are: • Fuses should be installed on the ungrounded side of the circuit to ensure uninterrupted connection to the low potential when the fuse opens. • Some advanced cooling solutions require that the placement of the fuse be reconsidered. For example, fuses should not be submerged in liquid-immersion cooling applications because the fuse element’s temperature will be so well controlled that an overload condition cannot produce sufficient heat to open the fuse. • Depending on the selected fuse’s size and rating, currentcarrying conductors and PCB traces must be sized to safely

carry 150 to 200% of the fuse current rating with acceptable temperature rise depending on applicable safety standards. • When a module is sourced by a dual-biased supply in which two series voltage sources are connected at the center to a common ground, separate fusing of both the positive and negative terminals is required. In this special case, a lineto-ground fault from either side of the system is possible, so protection on both sides is necessary.

Transient suppression circuits

Power modules will experience some adverse operating conditions during their lifetimes in any application. In particular, the power system and the power modules must be capable of withstanding surges or spikes, which are usually outside the specified operating range of the power modules.

Spikes and surges occur typically due to inductive load switching, motor speed changes in a system or the clearing of a fault, or a momentary power interruption. Spike-type transients are usually very short duration, but they can have a very high voltage peak. On the other hand, surges typically present somewhat lower peak voltages but may last for an extended period of time.

Two-stage transient-suppression circuit example consisting of a TVS diode stage and an active clamp stage.

Transient spike and surge profiles.

To qualify spikes and surges, consider the application type and the requirements of any applicable standards that deal with these transient events. With those parameters, it is then possible to design a two-stage protection circuit at the power module’s input, as in the following figure.

The first stage uses transient voltage suppression (TVS) diodes to control spikes by providing fast transient energy damping on the order of 100μs. These protect against high-voltage and lower-energy spikes and may be coupled with a downstream LC filter that serves to integrate the transient energy.

There are four main parameters to consider when selecting TVS diodes: reverse standoff voltage of the diode, breakdown voltage, clamping voltage and peak pulse current. The reverse standoff voltage (VR) of the diode must be within the DC-DC converter’s range of operation. In other words, the maximum working voltage of the protected circuit should not be exceeded before the TVS diode enters reverse breakdown. Next, consider the two higher thresholds that dictate the TVS diode’s operation: breakdown voltage and clamping voltage, both of which need to be less than the maximum instantaneous voltage the DC-DC module can tolerate. The breakdown voltage threshold, typically 110 – 115% of VR, is where the TVS diode will go into avalanche breakdown and shunt transient energy away from the power module. The second, higher clamping voltage threshold (typically 130 – 140% of VR) is only reached when a large amount of current flows through the diode. Lastly, consider the peak pulse current rating, which is the maximum current the TVS diode can withstand.

The second stage of the transient-suppression circuit deals with more prolonged-duration surge events. A series FET serves as a linear voltage regulator to actively clamp the module input voltage within an acceptable range. Again, the selection of this FET is dependent on the acceptable input voltage range of the module.

When selecting a FET, remember that it should be rated to withstand the peak surge voltage amplitude if the FET must be completely disabled. It must also be rated to conduct the full module input current when fully enhanced during normal operation. Additionally, the FET must be capable of conducting the full load current at the input side and ought to have the lowest RDS(ON) possible to minimize power losses. Finally, evaluate the specified operating area (SOA) and transient thermal impedance against the specific clamping conditions the FET will perform for the circuit.

Conclusion

Now, with a system built and protected, the next area of concern is specific to the load the DC-DC module will supply. The next tutorial in this series will address some special considerations in this area.

Mouser Adds More Than 2,370 New Parts

element14 Offers Connective Peripherals Products Avnet Appoints Ernest Maddock

Mouser Electronics has added more than 2,370 new parts in July 2021, to give its customers an edge and helping speed time to market. Over 1,100 semiconductor and electronic component manufacturer brands count on Mouser to help them introduce their products into the global marketplace. Mouser's customers can expect 100% certified, genuine products that are fully traceable from each manufacturer. Last month, Mouser launched more than 2,370 products ready for shipment. Some of the products introduced by Mouser last month include: • Analog Devices LTC7811 Triple-Output Buck/Buck/Boost

Controller

Analog Devices LTC7811 is a high-performance, triple-output (buck/buck/boost) DC/DC switching regulator controller that drives all N-channel power MOSFET stages. • Crowd Supply WallySci E3K Bio-Sensing Platform Crowd Supply WallySci E3K bio-sensing platform provides an affordable, fully open-source, wireless framework for an intuitive understanding of bio-signals originated from the human heart, muscle, and brain. • Phoenix Contact Axioline Smart Elements Phoenix Contact Axioline Smart Elements, an extension of the Axioline F input/output (I/O) system, provide compact digital, analog, and function modules for automation applications.

element14 has entered into a new global distribution agreement with Connective Peripherals that will enhance its range of market-leading connectivity products for customers. The addition of Connective Peripherals expands element14’s existing portfolio of products for field and lab-based engineers in a wide variety of applications where it is necessary to connect to instruments or systems via serial ports to carry out field-based configuration, upgrades and maintenance. The product range enables modern PCs and laptops to use a USB Type C port to connect directly to legacy serial interfaces such as RS232/RS422/RS485, CANbus, SPI, I2C, or JTAG. All adaptors and cables feature built-in electronics, making it easy to connect to any equipment. The cables are also available with connectors, bare ends or single-pole female receptacles, enabling use with systems that offer D-type connectors, header connectors or which require wires to be soldered to the board.

EMA Design Automation, Digi-Key Partners

EMA Design Automation and Digi-Key Electronics have partnered to release the OrCAD Capture Bundle, a special offer available only on digikey. com. This new design bundle provides the tools, data, and models needed to ensure first-pass design success including: • OrCAD Capture, the industry-standard schematic design solution • In-design ability to search and select parts from Digi-Key • Searchable cloud library of schematic symbols connected to Digi-Key parametric data • Integrated sourcing tools to procure parts quickly and easily from Digi-Key • OrCAD e-Learning, including certification opportunities

This unique collaboration furthers both EMA's and Digi-Key's goal of increasing the efficiency of engineers by providing the tools they need to streamline the design process. Now, engineers can focus on design, eliminate tedious tasks, quickly innovate, and keep the design process moving forward, all within a single unified design environment.

With the current uncertainty in the global electronics supply chain, it is more critical than ever that engineers have access to the information they need to make informed part decisions.

Avnet has named Ernest Maddock to the company's board of directors, effective immediately. Maddock will serve on the board’s Audit and Finance Committees. Maddock brings extensive technology industry knowledge and financial experience. He retired from Micron Technology in 2018, having held the position of Chief Financial Officer and advisor. He previously served as CFO at Riverbed Technology (2013-2015) and LAM Research Corporation (2008-2013). In addition, he held various financial and accounting positions throughout his 40-plus year career, including with NCR Corp. and Lockheed Martin.

Maddock serves on the board of Ultra Clean Holdings, Inc., a developer and supplier of critical subsystems for the semiconductor capital equipment industry focusing on gas delivery systems.

He holds an MBA from Georgia State University and a bachelor’s in industrial management from the Georgia Institute of Technology.