EEWeb Pulse - Volume 42

EEWeb

PULSE

EEWeb.com

Issue 42 April 17, 2012

David Arthur

SouthWest NanoTechnologies, Inc. (SWeNT)

Electrical Engineering Community

TA B L E O F C O N T E N T S TABLE OF CONTENTS

4

David Arthur SOUTHWEST NANOTECHNOLOGIES, INC. Interview with David Arthur - CEO

Single Wall Carbon Nanotubes Enable Printed Electronics

10

BY DAVID ARTHUR

How SWeNT is tapping into the unused potential of carbon nanotubes and creating a standard for thin film production.

Featured Products Electric Overstress (EOS) and Its Effects on Today’s Manufacturing

13 15

BY VLADIMIR KRAZ WITH ONFILTER How this device-damaging phenomenon can be prevented by using EMI filters in the production environment.

The Story of James Clark Maxwell and Switched Capacitor Filters

22

BY PHILIP GOLDEN WITH INTERSIL

One-hundred years after their discovery, Maxwell’s switched capacitor filters revolutionized the modern analog circuit industry.

RTZ - Return to Zero Comic

EEWeb | Electrical Engineering Community

25

Visit www.eeweb.com

3

DA INTERVIEW

FEATURED INTERVIEW

avid

rthur

SouthWest NanoTechnologies, Inc. Will you tell us about your 25+ years of experience commercializing products utilizing advanced materials?

I graduated with a BS in Chemical Engineering from Tufts University in 1980. My first job was in R&D with a specialty materials company, Rogers Corporation. During my 14 years there, I worked in R&D, Manufacturing and Marketing. My main area of responsibility was circuit materials for Microwave, RF and High Speed Digital electronics packaging. I was actively involved with developing copper-clad dielectric materials based on fluoropolymers filled with glass microfibers and/or ceramic particles. Dielectric constant was controlled over a range of about 2 to 10 or so. These materials enabled very low loss signal transmission at high frequencies (10 GHz +), as well as low cross talk and fast rise times for digital packaging.

I was also involved with working with leading companies like IBM on developing novel fabrication methods for making high density multi-layer printed circuit boards for high performance computing applications. These circuit boards were designed to enhance reliability

EEWeb | Electrical Engineering Community

during thermal cycling of plated thru holes and also solder joints of ceramic components surface mounted to the circuit boards. While working at Rogers, I attended the University of Connecticut part-time and received an MS in Chemical Engineering in 1990.

David Arthur - CEO

Visit www.eeweb.com

4

INTERVIEW

In 1998, I took a CEO position at TPI Composites, a leading producer of sailboats, including the J-Boat brand.

TPI had a patented manufacturing technology (SCRIMP) that allowed large-scale structural composites of complex shape to be fabricated at higher quality, lower cost and lighter weight than alternative technologies. This process was great for making sailboat hulls and

was also used to make wind blades, bridge decking and transportation vehicles of various types (including large refrigerated rail cars). During the short time that I was there, we increased the profitability of the boat business, completed an M&A deal with Hardcore Composites (the merged company was called

I would not say that I have any “tricks.”

Success comes the old fashioned way; developing unique skills, hard work, personal integrity, building relationships, and not being afraid to take risks and innovate.

Composite Solutions) and started up a new plant to build refrigerated rail cars. After successfully producing the first dozen 72 foot long rail car prototypes, we signed a very large contract with a leading company in the rail industry. I left a short time later, as the previous CEO and founder really wasn’t ready for retirement and he came back to more actively engage in the business.

EEWeb | Electrical Engineering Community

In 1999, I became VP of Strategic Programs at Helix Technologies, a leading producer of cryogenic vacuum pumping systems. This was right around the time when “dot com’s” were the rage. Helix wanted to grow its service business with a disruptive technology platform called GOLDLink Support (Global On-line Diagnostic Link to Customer Support). GOLDLink allowed Helix provide remote diagnostic monitoring of sputtering and ion implantation tools used in semiconductor fabs around the world, enabling predictive maintenance practices (eliminating unscheduled downtime), improved vacuum process control and lower cost of equipment ownership for the fabs. GOLDLink also enabled Helix to re-engineer its service deliver process, significantly improving the profitability of the service business. My main responsibility at Helix was to lead the team to complete the development of the GOLDLink platform and launch goldlinksupport.com, which was a major success for Helix. After a few years, however, the semiconductor industry went into another down cycle, which put a hold on the next phase of our expansion plan. At about this time, “nanotechnology” was the rage, so I decided to return to my roots (materials science) and seek opportunities in nanotechnology.

In 2001, I became COO of Eikos, a developer of materials for the DOD and selected commercial applications. I was asked to help analyze Eikos’ IP portfolio and figure out what opportunities there were for commercializing “products” based on differentiated technology.

Visit www.eeweb.com

5

FEATURED INTERVIEW

In 1994, I joined A.T. Cross, a high quality writing instruments company.

I was hired to lead the start-up of Cross Pen Computing Group. This was part of a strategy to grow the company by diversification and also to address the risk that dramatic growth in e-communications was reducing the use of conventional writing instruments. After a few years of development, we launched several products for pen computing.

Our flagship product was the CrossPad, which was a personal digital notepad. It enabled the user to write on conventional paper with “physical ink” and capture all the pen strokes in the form of “digital ink.” This was accomplished by transmitting an RF signal from the pen tip and receiving this signal in a thin antenna grid discreetly mounted under the pad of paper. The user could then upload the notes to a PC for storage, editing or translation to typed text. Handwriting recognition software was licensed from IBM. The first Christmas selling season, we sold $25 million of CrossPads.

This was a very busy time for me, as shortly after joining Cross, I became VP of Engineering for the Writing Instrument side of the company.

I also attended an executive MBA program at Northeastern, graduating with an MBA in 1996.

INTERVIEW

In 2005, Bob Praino and I cofounded Chasm Technologies, a consulting firm that helps its clients commercialize products through smart application of materials science. The sweet spots for Chasm are projects that include nanomaterials, roll-to-roll coating, manufacturing processes and/or specialty equipment design and build. There are nine people who work at Chasm and most of them have several years experience at Polaroid. SouthWest NanoTechnologies (SWeNT) was one of Chasm’s first clients. Soon after forming Chasm, Professor Resasco contacted me to see if I would be interested in being CEO at SWeNT. To make a long story short, I declined a few times, but after meeting with him and then Chairman Skip Porter, I said yes.

At the time I joined SWeNT, the

organization consisted mainly of post-docs from Resasco’s team and the scale of operations was quite small (pilot scale). Over time, we added several people to the team with industrial experience and we focused on scaling up the manufacturing technology. This led to the construction of a large-scale 18,000 SF manufacturing plant on an 8-acre site in Norman, OK. This plant put SWeNT on the radar screen of any serious developer of carbon nanotube enabled products.

In 2009, SWeNT’s material was recognized by NIST as the starting material for its Standard Reference Material program for carbon nanotubes. This was an honor for us.

SWeNT is now focusing on commercializing products that are tailored for target applications. One of the things that sets SWeNT apart is a willingness and ability to tailor products for target applications.

In 2009, SWeNT also formalized its strategic alliance with Chasm, jointly

EEWeb | Electrical Engineering Community

establishing a Carbon Nanotube Applications Development Center at Chasm’s facility in the Boston area. This relationship and this center have been key to commercializing SWeNT’s carbon nanotube products, especially for Printed Electronics applications. In 2010, SWeNT became the first US manufacturing company to get a consent order from EPA to make and sell commercial quantities of singlewall carbon nanotubes. In 2011, SWeNT also received a consent order from EPA for its specialty multiwall carbon nanotube products.

In 2011, SWeNT signed a license agreement with Chasm’s V2V™ ink technology, which enables SWeNT to make and sell unique ink products that allow carbon nanotubes to be printed at low-cost using standard industrial printing equipment. The combination of SWeNT’s unique ability to control carbon nanotube structure via selective synthesis and SWeNT’s unique ink platform is opening the door to nice business opportunities in electronics materials. Also in 2011, SWeNT commercialized its SMW™ specialty multi-wall carbon nanotube product, which offers better ease of dispersion and higher conductivity versus traditional multiwall products. This is opening the door to great business opportunities in the composites materials area.

Will you tell us about some of your studies in synthesis of nanomaterials and the fabrication of nanoscale features at a large scale?

I have been actively involved with synthesis of carbon nanotubes since joining SWeNT in 2005.

While at Chasm, I have had the

Visit www.eeweb.com

6

FEATURED INTERVIEW

At that time, Eikos’ revenues were primarily R&D contracts and federal grants. This led to the development of carbon nanotube ink technology, which allowed transparent conductive films to be made using spraying methods. These carbon nanotube films were more flexible and more neutral in color than Indium Tin Oxide (ITO). As part of the commercialization plan, I helped Eikos raise equity capital and negotiate agreements with strategic partners. It was at this time that I met Professor Daniel Resasco from the University of Oklahoma. I was convinced then (and remain so today) that the CoMoCAT® process that he invented was the best way to make single-wall carbon nanotubes of controlled structure at large-scale and low-cost.

INTERVIEW

What are your key attributes that have helped you get to where you are today?

I guess I have a nice combination of technical competency and business skills that enable me to work well with leading researchers and help figure out how to commercialize technology to create a successful business. There are many very good technical people and very good business people, but much fewer people that are good at both.

What is on your bookshelf?

Crossing the Chasm by Geoffrey Moore. This book is partly what inspired us to form Chasm Technologies. The Four Agreements: A Practical Guide to Personal Freedom by Don Miguel Ruiz. This book has helped me stay balanced. For fun, right now I am reading Dead or Alive by Tom Clancy.

Do you have any tricks up your sleeve?

I would not say that I have any “tricks.” Success comes the old fashioned way; developing unique skills, hard work, personal integrity, building relationships, and not being afraid to take risks and innovate.

Do you have any note-worthy engineering experiences?

The past two years, I was honored by the NanoBusiness Alliance as being

one of the most influential people in the field of Nanotechnology. Over the years, I have had the opportunity to work with some outstanding people and have accomplished some nice things. A common theme for me has been working on commercializing advanced technologies to enable disruptive product platforms. Two very nice examples of this are GOLDLink and what we are doing at SWeNT right now. I also have more than 25 patents on which I am listed as an inventor.

Do you continue to have an active role in product development? If so, how?

Yes, I am quite actively involved with product development at SWeNT. I also contribute in an advisory role at Chasm on projects unrelated to SWeNT. Can you tell us more about SWeNT, its goals and the technology it’s developing?

SWeNT is now focusing on commercializing products that are tailored for target applications. One of the things that sets SWeNT apart is a willingness and ability to tailor products for target applications. Our target markets include materials for electronics and materials for composite applications. We have what you could call a sort of roadmap for the particular segments that we target. The segments we are going after are transparent conductive films (TCF) applications, which are used by various types of displays, lighting and solar applications.

So we are actively pursuing those types of applications for our carbon nanotubes. For that application you need a nanotube product that

EEWeb | Electrical Engineering Community

allows the customer to fabricate a thin film touch sensor pattern at low cost with the right combination of optical transparency and electrical resistivity. There are a lot of materials that are conductive, a lot that are transparent, and a fairly small number that are both electrically conductive and optically transparent. There is an even shorter list of materials that are optically transparent, electrically conductive and can be printed at low cost. The material that dominates the industry, and has done so for the last four decades, is indium tin oxide (ITO).

It is basically a ceramic thin-film material that is vacuum-deposited and then subtractively patterned using photolithographic etching techniques. The carbon nanotube inkss that we make are less expensive than ITO on a materials basis, but more importantly, when you can directly print the touch sensor patterns versus having to go through the multiple steps of the subtractive method. This will result in significantly reduced cost.

Do you provide the core material for customers to use?

We have to control the structure of the carbon nanotube material that we make. We make two types of nanotubes: one is called the single-wall carbon nanotube, which has one wall of carbon on a tiny diameter of 1nm, with a length of about 1,000 times that. These are the highest-end variety of nanotubes, and they are mainly used in thinfilm applications for electronics.

The other type, at the other end of the spectrum, is a material called multiwall carbon nanotubes.

These are larger in diameter—

Visit www.eeweb.com

7

FEATURED INTERVIEW

opportunity to work alongside Bob Praino and other team members on several interesting projects that include roll-to-roll printing and also nanoimprint lithography for applications in displays, pharma and other industries.

INTERVIEW

Is this a process that is easy to control, or do you typically get a variety of nanotubes?

A variety. It’s one of the big limitations when you don’t know exactly what results you will get. Typically there are certain chiralities or nanotube structures that are preferred more than others. Also, the coexistence of two different types of structures can result in defects. One good example is another type of application—thin film transistors (TFTs). With these, you want to put a semiconducting thin film—not necessarily a conducting thin film—between the source and drain electrodes, between which you do not want to have any leakage current. You want to have very well-defined on/off states.

If you have a mixture of nanotubes with metallic conducting electronic properties, and nanotubes that have semiconducting electronic properties, you can end up with a very poor on/off ratio. So it’s important to control the structure of the tube for electronics, and SWeNT

is better than anyone else at doing that.

How reliable is the nanotube printing technology?

There is obviously a lot more knowledge about the material (ITO) that has been industry standard for the last four decades, so no matter what we do, the proven and established material will initially be more comfortable for prospective customers. But I would say there are areas where ITO is weak with respect to reliability, specifically because it is made from a ceramic thin film, it is quite brittle. So if there is any flexing involved, the ITO is very likely to crack, which presents a reliability problem. That has been a big issue in touchscreens, for example, where certain touchscreen designs require some flexing, and the main failure has indeed been cracking of the ITO. This is a weak point for the ITO and a strong point for the carbon nanotubes. However, there is still a learning curve with carbon nanotubes; you have to recognize that everything is a system. It isn’t just carbon nanotubes, but you must also know onto which substrate it is being printed, what optical adhesive is being used to bond it to the structure, and usually something has to make electrical contact. With all of these system parts, there is a lot of learning that goes on.

But because the cost-reduction potential is compelling—about 80 percent—we see that along with the learning there is a lot of opportunity.

We’re aiming to have our nanotubes be a part of the rapidly growing touchscreen movement.

development project with Panasonic Boston Laboratory (PBL). We’re working together to qualify a singlewall carbon nanotube ink that will be used as semiconducting thin film material for TFT backplanes in OLED TVs. OLED TV is a major area of focus for Panasonic, and it seeks a position of leadership.

The biggest issue with this goal is the high current cost of OLED TV technology compared to alternatives. So there is a desire to significantly reduce the cost of the TFT backplane by printing it inexpensively on plastic materials.

Using a significantly less expensive TFT backplane will enable a more competitive price for OLED TV. With regard to the printing, the technology has to be good enough to print the features of a TFT with a channel length of about 10 microns or less. This is pushing the envelope for a number of printing technologies. We are working with PBL first to establish the recipe for making a nanotube that meets the performance criteria. Second, we’re formulating an ink and establishing the printing system for it that is capable of printing the required feature sizes printed over a large area. PBL is focusing on the latter, and the former’s is coming from SWeNT. I believe that further down the road printed transistors is going to be an even larger market for us than touch technology. ■

In the TFT area, we have a joint

EEWeb | Electrical Engineering Community

Visit www.eeweb.com

8

FEATURED INTERVIEW

about 10 times—and have usually 10 or more walls, hence the name multiwall carbon nanotubes. If you look at these materials, you’ll see that they are graphitic. Graphite likes to be multilayered, so it’s a lot easier to make a multiwall nanotube; it’s really what wants to happen. In addition, the singlewall is unique because its optical and electronic properties can be changed by manipulating diameter and orientation of the carbon in the sidewall. The combination of diameter and orientation is called chirality. Each combination of diameter and orientation gives you a unique nanotube.

Avago Technologies LED Lighting Solutions Technology

Any Color. One Device.

Avago Technologies Moonstone 3x1 Watt TM

RGB High Power LED gives you a reliable, energy efficient, long life operation product for ease of design in any type of color mixing application.

MoonstoneTM Tri-color Power LED light source from Avago Technologies: ASMT-MT00 Avago’s MoonstoneTM Tri-color Power LED light sources are high performance energy efficient devices which can handle high thermal and high driving current. The exposed pad design has excellent heat transfer from the package to the mother board.

The advanced 3x1Watt RGB MoonstoneTM package delivers typical 108 lumens at 350mA. The robust package design makes it an excellent choice for color mixing applications.

Applications • Architectural Lighting • Decorative & Mood Lighting • Retail Lighting • Garden lighting • Show Lighting For more information or to request a sample please go to:

www.avagotech.com/led

Single Wall Carbon Nanotubes Enable Printed Electronics David Arthur -

CEO Southwest NanoTechnologies, Inc. (SWeNT)

Single wall carbon nanotubes (SWCNT) have long been recognized as having unique electronic and mechanical properties that could enable important advances in electronic devices, most notably for printing thin films for printed electronics applications, such as Thin Film Transistors (TFTs) and Transparent Conductive Films (TCFs.) This potential has not as yet been significantly exploited for several reasons.

With respect to TFTs, the potential advancements derive primarily from the inherent electrical properties of semiconducting SWCNT. SWCNT can be semiconducting or conducting, depending on the specific structure or ‘chirality’ of the nanotube1.

Semiconducting SWCNTs demonstrate greater intrinsic mobility than any other known semiconducting substance,

and can be room temperature processed. Furthermore, the electronic band structure of semiconducting SWCNT facilitates high on/ off ratios. Amorphous silica and organic TFTs have both received considerable attention for TFTs, but both exhibit comparatively low mobility and, in the case of amorphous silica, high temperature processing is required. This situation was summarized graphically by Sun, D. M. et al.2 as shown in Figure 1, who used semiconducting SWCNT to make TFT devices with on:off ratios in the region of 106 and mobility between 10 and 100 cm2 V-1 s-1.

With such desirable semiconductor properties, why have semiconductor devices employing SWCNT not been commercially successful?

EEWeb | Electrical Engineering Community

Typically, these results have been achieved using SWCNT that have been extensively purified to enrich the semiconducting tube content.

Indeed, Zhou et al.3 have shown that a minimum of 95% semiconducting tubes is desirable to obtain good

Visit www.eeweb.com

10

PROJECT (organic crystal)

Mobility (cm2 V-1 s-1)

100

Ref. 23 (LTPS)

Ref. 3

Ref. 13

p-Si

Ref. 21

Ref. 24

10

(InGaZnO)

Ref. 22 Ref. 17 Ref. 10 Ref. 18

1

Ref. 25 (Organic)

Ref. 5 Ref. 14

a-Si

Ref. 20

0.1

Organic27

This Study Other nanotube TFTs p-Si, a-Si, oxide, organic

0.01 100

101

102

103

104

105

106

On/off ratio

107

108

Figure 1: Comparison of On:Off ratios and Mobilities for TFTs made from different maerials2

105

10 8 6

Measurement

104

Simulation

2 0

0

2

4

6

8

10

12

14

16

18

20

10 8

On/Off Ratio

4

103

Separated Nanotubes CVD Mixed Nanotubes Simulation Nanotubes

102

6

Simulation

101

4

Measurement

2 0

0

2

4

6

8

10

Black = Metallic CNT

12

14

16

18

20

100 0

Gray = SC CNT

20

40

60

80

100

Channel Length (µm)

Figure 2: Effect of proportion of semiconducting tubes in coating. (a) Schematic showing that a small percentage of metallic tubes can be tolerated without creating a conductive path and (b) Effect of removing metallic SWCNT on TFT performance.

TFT performance, as seen in Figure 2. Statistically, as manufactured SWCNT are expected to have 67% semiconducting tubes and 33%metallic tubes, this is indeed the case for most manufacturing processes.

To obtain SWCNT material suitable for TFTs from these materials requires extensive

and expensive purification and tube separation processes to remove the metallic nanotubes, which can lead to degraded semiconductor properties and very low yields.

For TCFs, the promise for better transparent conductive films derives from the inherent high conductivity

EEWeb | Electrical Engineering Community

of the material, the unusually high aspect ratio (~1,000) and extreme mechanical strength.

These properties enable the manufacture of highly conductive, flexible films that are also transparent. However, producing the best SWCNT for this purpose has been limited by the availability of consistent SWCNT of sufficient purity. Furthermore, most applications for conductive thin films, including touchscreens, flexible displays, sensors, etc. require the CNT to be patterned, and cost-effective ways of achieving this with CNTs have not been available.

SouthWest NanoTechnologies has addressed these concerns.

The CoMoCat® process4 uses a supported catalyst in a fluidized bed reactor. This provides very precise and uniform control of reaction conditions allowing the selective growth of either semiconducting or metallic enriched SWCNT. Thus, by careful design and production of the catalyst, together with precise control of the reaction conditions, SWCNT material with > 95% semiconducting tubes can be realized directly from the reactor, negating or substantially reducing the need for expensive secondary operations. Similarly, by modifying the catalyst design and varying the reaction conditions tubes can be produced that are 70% metallic in nature, enhancing the conductivity of TCFs. This process produces tubes of high purity with very little evidence of other forms of carbon and minimal residual catalyst. Figure 3 shows a TEM of the CoMoCAT product after purification to remove the residual

Visit www.eeweb.com

11

FEATURED PROJECT

Ref. 26

PROJECT

catalyst and catalyst support.

SWeNT has combined this synthesis technology with proprietary ink technology to allow nanotubes to be printed by conventional means, such as screen, pad and gravure printing. This V2V™ technology licensed from our sister company

Thus, combining this ink technology with the SWCNT synthesis capability gives a practical solution for printing both conducting and semiconducting electronics by conventional and well established printing methods. To date, SWeNT has produced TCFs with surface resistance < 300 Ω/□ at 90%T. Initial results for TFTs show that on/off

1) Mix

2) Print

ratios of 105 can be produced with the current materials. With further development, it’s anticipated that an on/off ratio of 106 can be achieved.

References 1. Wildöer, J.W.G.; Venema, L.C.; RinzlerA.G.; Smalley, R.E.; Dekker, C. Nature 391, 59 (1998) 2. Sun, D.M.; Timmermans, M.Y.; Tian,Y.; Nasibulin, A.G.; Kauppinen, E.I.; Kishimoto, S.; Mizutani, T.; Ohno, Y. Nature Nanotech. 6, 156 (2011) 3. Wang, C.; Zhang, J.; Ryu, K.; Badmeav, A.; De Arco, L.G.; Zhou, C Nano Lett. 9 4285 (2009) 4. Resasco, D.E.; Alvarez, W.E; Pompeo, F.; Balzano,L.; Herrera, J.E.; Kitiyanan B.; and Borgna, A. Journal Nanoparticle Research 4, 131 (2002) ■

3) Dry

V2V™ Vehicle

SWeNT™ CNT Ink CNT Paste

SWeNT™ CNT Ink

SWeNT™ CNT

Figure 4: Schematic of V2V® Ink Printing Process

EEWeb Electrical Engineering Community

Join Today www.eeweb.com/register

EEWeb | Electrical Engineering Community

Visit www.eeweb.com

12

FEATURED PROJECT

Figure 3: TEM of CoMoCAT® SWCNT Showing high purity long SWCNT bundles.

Chasm Technologies allows SWCNT to be dispersed in an organic vehicle without the use of surfactant. This dispersion is then combined with an ink vehicle which controls the rheological properties of the ink, which can be adjusted for the requirements of different printing technologies. All components of the ink with the exception of the SWCNT are fugitive and easily removed by heating the ink in a forced air oven for a few minutes at 100 to 120°C. The process is shown schematically in Figure 4.

F E AT U R E D P R O D U C T S Agilent Technologies Inc. introduced Infiniium 90000 Q-Series oscilloscopes with industry-leading, real-time bandwidth of 63 GHz on two channels and 33 GHz on four channels. The new lineup includes 10 four-channel models ranging from 20 GHz to 63 GHz, all of which are bandwidth upgradeable. These new scopes deliver the lowest noise and have the lowest jitter measurement floor in the oscilloscope industry, ensuring superior measurement accuracy. “The 90000 Q-Series represents another breakthrough for Agilent Infiniium oscilloscopes,” said Jay Alexander, vice president and general manager of Agilent’s Oscilloscope Products Division. “In the last five years, we have introduced oscilloscopes with the deepest memory, the lowest noise floor and the highest bandwidth.

The 90000 Q-Series is the culmination of all these innovations, and it features all three industry-leading characteristics to help engineers design and validate devices that use emerging technologies.” For more information, please click here.

Nano Current Voltage Monitor Linear Technology Corporation introduces the LTC2960, a 2.5V to 36V, two input voltage monitor that draws only 850nA of quiescent current, offering extended battery life in battery-powered applications. The LTC2960 provides two adjustable monitoring inputs that can be configured to provide undervoltage (UV) or overvoltage (OV) monitoring, low battery indication, undervoltage lockout (UVLO), power supply sequencing signals or a high voltage window comparator for microprocessor, DC/ DC switcher or LDO based systems. The LTC2960 fulfills a broad range of battery-powered, portable application requirements with its wide voltage operation and low current consumption in a tiny 2mm x 2mm DFN or ThinSOT™ package. For more information, please click here.

Low Cost USB 3.0 Analyzer LeCroy Corporation, the worldwide leader in USB test solutions, today introduced a new USB 3.0 protocol analyzer designed to significantly lower the cost of developing and testing new SuperSpeed USB devices.

Based on LeCroy’s Advisor T3 Standard Edition (currently the top selling USB 3.0 protocol analyzer), the new Basic model at $2995 provides the same lossless data capture with full support for USB 3.0, 2.0 and 1.1 analysis. Now that Intel is shipping USB 3.0 in their 7 Series Chipset, the Advisor T3 Basic is well suited to meet the feature and budget requirements of the cost-conscience mainstream market as companies seek to develop new USB 3.0 products and add USB 3.0 performance to their existing products.

For more information, please click here.

EEWeb | Electrical Engineering Community

Visit www.eeweb.com

13

FEATURED PRODUCTS

Fastest Real-Time Oscilloscopes 63-GHz

EEWeb Electrical Engineering Community

Contact Us For Advertising Opportunities

1.800.574.2791 advertising@eeweb.com

www.eeweb.com/advertising

Electric Overstress and Its Effects on Today’s Manufacturing

Vladimir Kraz

President, OnFILTER, Inc.

Electrical overstress, or EOS, is a phenomenon where electrical signals applied to a circuit or a device exceed normal operating parameters. These excessive electrical signals are abnormal by definition and are not a part of normal operation of the devices. According to Intel1 , EOS is the number one cause of damage to IC components. In the broadest terms, EOS also includes electrostatic discharge (ESD), however, commonly EOS is used for excessive signals other than ESD and this is how it will be used in this paper. Here we will discuss the effects of electrical overstress on devices and equipment, the origins of EOS, its propagation, as well as mitigation of EOS in production environment.

EOS and ESD Most readers are quite familiar with electrostatic discharge (ESD) and its adverse effects on electronic equipment and components. EOS, while technically encompassing ESD, is differentiated from ESD in a

ESD Event

number of ways: Effect of EOS on Devices A typical semiconductor device can be damaged by an ESD Event with

EOS Event

Caused by a rapid discharge of accumulated electrical charge. Once this accumulated charge is consumed, ESD Event can no longer manifest itself.

Caused by voltage and/or currents associated with operation of equipment or with power generating equipment. Lasts as long as the originating signal exists. There is no inherent limitation on it’s duration.

Characterized by a specific waveform. While the waveforms of different models of ESD Events (CDM, HBM, MM and others) certainly differ in appearance, in general their properties include rapid rising edge (within few nanoseconds) and an asymptotic rear edge lasting typically less than 100nS.

Can technically have any physically possible waveform – the sources of EOS are often unpredictable. There are some major categories, however, which will described further in the text.

Non-periodic and non-repeatable – accumulation of charges cannot be guaranteed.

Mostly, but not always periodic and repeatable.

EEWeb | Electrical Engineering Community

Visit www.eeweb.com

15

TECHNICAL ARTICLE

The effects on the device from an ESD Event and an EOS Event can be very different. At the risk of oversimplification, the following example can be helpful. An ESD Event could be compared with emptying a cup of water on a floor.

There is a resulting small puddle, but once the content of a cup (i.e. charge) is gone, there is no more water coming and the damage from the spill is thus limited. An EOS event, however, could be compared with an open faucet. However little water it may drip in comparison with the sudden pour of water from the cup, with time this trickle may flood the entire floor and cause significant damage. The duration of typical EOS Events is several magnitudes longer than the duration of most ESD Events (microseconds or even milliseconds vs. nanoseconds) – thousand or even a million times longer; therefore this comparison “holds water.”

According to Craig Hillman , one of the mechanisms of damage due to EOS is thermal runaway from Joule heating (excessive current).

This is also systemic to ESD Events as well. While overheating due to ESD requires a significant current injection over a few nanoseconds, a much smaller EOS Event that would last thousands or even millions

signature of EOS-caused damage is similar to that of the Charged Board ESD model (CBM) due to the similarity in energy of the event.

Figure 3 shows another example of damage due to EOS. High energy of EOS Event melted the bonding wire of the device.

To the author’s knowledge, at the present there is no established correlation yet available between the levels of damage due to ESD and the ones due to EOS. This paper recommends that such relationship is examined by the experts in the industry and, if possible, a correlation is established for the benefits of the industry.

EOS Effect on Equipment

Figure 2: EOS Damage of Semiconductor Device. Source: Intel

times longer – microseconds or milliseconds – may generate a similar amount of heat.

EOS often causes massive damage of the device due to its high energy, as shown in Figure 2. Sometimes the

Device damage is not the only negative effect of unwanted electrical signals.

Electronic equipment can be susceptible to noise on power lines and ground.

Transient spikes all too common on power lines can add an “extra” pulse on digital lines (Figure 4) and cause numerous other problems – anywhere from sensor misreading to outright equipment lockup. Since most of production equipment today has significant electronic content, this problem cannot be ignored.

Please see more on this subject here 4,5,6,7.

Types of EOS in Production Environment

Figure 3: Damaged Wire Bond. Source: SEM Labs.

EEWeb | Electrical Engineering Community

There is a large variety of types of EOS occurrences in a typical production environment. This paper outlines the most common types and provides brief description of their properties and their most likely origins.

Visit www.eeweb.com

16

TECHNICAL ARTICLE

magnitude of anywhere from 100V to 250V CDM (of course, the overall damage range is much wider).

EOS-induced damage, however, occurs at much lower levels. IPCA-6102 (§3.1.1) and IPC-77113 (§2.11), the standards used by PCB assembly plants to control quality of electronic assemblies, recommend that the EOS levels should be kept below 0.5V and in case of sensitive assemblies – below 0.3V. Why is there such a discrepancy in damage voltage levels? This has to do with the waveforms of exposure, not just absolute voltage levels. Similar discrepancies exists between different ESD discharge models – the same device may be damaged by 2000V HBM model, while being sensitive to 100V CDM model discharge.

TECHNICAL ARTICLE

Current Induction Noise Disturbance

An “Extra” Pulse

Figure 4: Noise on Power Line Affecting Equipment

Mains-Caused EOS (AC 50/60Hz) Voltage Induction Since most equipment operates on AC power from the mains, it is not surprising that the mains’ artifacts can be present in some tools. Poor wiring schemes, lack of adequate grounding and ground loops are all contributors to this. There is a strong relationship between ground impedance and the AC voltage – the higher the ground impedance, the higher the resulting AC voltage8,9.

Neutral/Ground Reversal It is an unfortunate (and unsafe) occurrence when neutral and ground wires in the electrical outlet or inside the tool itself are reversed.

In the author’s experience this happens even in the best-run facilities in the world. To complicate the matters, conventional testers such as the ubiquitous three-light checker, which is obtainable from hardware stores, cannot test for

Whether in wires connected to motors or other current consumers in the tool or within the motors, heaters and other devices, strong currents generate magnetic fields, which can produce currents and voltages in largely accidental loops within the same tools. Spreading power cables away from data cables and wires and reducing loops mitigates this problem to some degree.

High-Frequency Noise on Power Lines and Ground High-frequency signals, or electromagnetic interference (EMI), on power lines are usually parasitic in nature (an exception to this is outlined below) and are a result of transient signals generated by operation of equipment such as stepper and variable-frequency motors, solenoids, relays and the like. The higher the power consumption of such a device the stronger the EMI signal. Figure 5 shows a typical signal on power lines generated

Equipment turning on and off

by EMI. As clearly seen, it is anything but a continuous waveform.

When assessing EMI signals for the possibility of EOS, it is imperative that instruments with the ability to capture the peak signal are used.

In the author’s experience, it is not uncommon to encounter spikes of up to 20V on ground and in power lines. Figure 5 shows some typical waveforms on power lines in a production environment.

There are cases, however, when the predominant signal in cables and wires is a continuous waveform.

Some examples are signals from servos and variable frequency motors.

Their fundamental frequencies lie typically below 20kHz. Another source is RFID readers. Passive RFID tags require strong magnetic field to power them up which results in strong induced signals into anything resembling a conductive loop, which are not difficult to find in production tools. The resulting voltage, with a typical frequency of 13.56MHz, then propagates through wires throughout the facility. While these signals are intentional and are used for specific purposes, when they spread outside of the equipment involved they are liable to create EMI-related problems.

Switched Power Supply

Thyristor Control (dimmer)

Figure 5: Typical Noise Waveforms on Power Lines

EEWeb | Electrical Engineering Community

Visit www.eeweb.com

17

TECHNICAL ARTICLE

this condition. In such a situation, the return current flows not through neutral but through ground wire, creating voltage on ground, which is never a good thing.

TECHNICAL ARTICLE

Soldering Irons

I

Z

V

Figure 6: Ground Bounce

Ground Bounce This phenomenon deserves special consideration for high frequency signals. Though mostly attributed to ICs and PCB layout issues, ground bounce is a significant factor for factory-scale signals. This paper6 provides adequate background of the phenomenon of ground bounce.

In short, when ground wire has substantial impedance at high frequencies, current passing through this wire from noise-generating equipment to ground produces voltage across this wire thus floating what was supposed to be the ground of the tool – see Figure 6. According to calculations in this paper7, this voltage may reach several volts at just a few milliamperes of current. This should trigger considerations for a proper grounding scheme.

Cases of EOS in Production Now that we discussed what phenomenon can cause EOS exposure, let’s examine some of the cases of EOS in real-life production environment and match them to

The tips of soldering irons touch the most sensitive electric components, therefore it is under the most scrutiny for EOS exposure. Some standards (MIL-STD-2000) require the tip of soldering iron to produce no more than 2mV of signal, which is quite unrealistic in most environments, especially given that the document does not limit the signal to only low frequencies. Papers such as this one8 were written on the subject. A voltage on a tip of a soldering iron can inject EOS signal into a sensitive component during soldering and damage it. Let’s take a look at why a soldering iron tip has voltage to begin with.

Bad Grounding Loss of Ground If a soldering iron loses ground, the tip of the iron can have any voltage up to ½ of the supply voltage to the iron. The voltage due to ground loss is usually AC 50/60 Hz. DC voltage on the tip would be contributed to other phenomenae, usually caused by a defective power supply in the iron itself. In the very best case, the voltage at the tip of the iron due to loss of ground would be equal to voltage on neutral which, as discussed before, is not zero and is typically several volts of AC. Loss of ground can occur within soldering irons themselves or in power outlets. Raytheon9 reported an occasion of massive failure of ground in power outlets which led

EEWeb | Electrical Engineering Community

to EOS and resulting damage in sensitive circuit. Reversal of ground and neutral also leads to excessive voltage at the tip.

Noise on Ground Whatever signal is present on ground, it will be present on the tip of the iron. Noise on ground can be quite high as discussed before. When the voltage on the tip is measured with a multimeter or an off-the-shelf iron checker, it will easily miss high-frequency signals and especially spikes that are typical in the production environment. It is imperative to be able to measure voltage with instruments that are capable of measuring high-frequency spikes.

A high-speed digital oscilloscope or a dedicated meter with highfrequency capabilities should be used.

Noise on Power Line Noise is propagated not only via ground but via power lines as well.

Transformers and power supplies converting mains voltage to 24V, for example, are often transparent to high-frequency spikes which end up on the soldering iron tip.

Spikes caused by commutation of equipment (e.g. heat gun, etc.) can also propagate through the power supply. The effect is similar to that which is caused by noise on ground and the signal should be measured in a similar fashion to what is mentioned above. Power line filters can help to reduce this noise.

Power Tools Power tools such as electric screwdrivers commonly used in electronic assembly may not always

Visit www.eeweb.com

18

TECHNICAL ARTICLE

the physical phenomenon which is manifested in each case. Only very few of such sources are outlined in this paper due to limitation of the scope.

TECHNICAL ARTICLE

Even the screwdrivers used in equipment for such a sensitive process as assembly of disk drives can generate significant voltage. As described in this paper10, voltage induced into a screwdriver’s ground Vs

-V

Motor Coil Zs

Tool Tip VI

Component

Tool (grounded)

1

Figure 7: High-Frequency Noise at the Tip of Power Screwdriver. Current at contact reached 180mA

wire by simply being routed in the same bundle as the wires to the stepper motor generated significant spikes (Figure 7)

TECHNICAL ARTICLE

have good grounding of the tips during rotation. Grounding via ball-bearings during rotation does not work since the lubricant in the bearing is insulative. In addition, some mains-powered screwdrivers may not have dedicated grounding since they may be using double insulation to satisfy safety requirements. Resulting voltage on the tip of the screwdriver may be quite high. The author observed 107V AC on the tip of a screwdriver used in the assembly of mobile phones in a 220V region.

Mitigation of EOS in Production Environment Good grounding with less than 1 Ohm impedance usually resolves most of 50/60Hz issues. Highfrequency noise, however, is quite a bit more challenging. The most effective way to deal with noise on power lines is EMI filtering which is included with recommendations

by Intell in the abovementioned document. EMI filters allow mains signals (50/60Hz 120/250V) to pass through, but greatly reduce extraneous noise. In addition to the power lines, it is also highly desirable to filter noise from ground as well, as it may carry a significant amount of noise throughout the factory.

Some equipment at your factory may already have some sort of EMI filter built in – equipment manufacturers do it in order to comply with emission regulations, such as FCC and CE. While such built-in filters help to reduce noise on power lines in the laboratory environment, they are much less effective in managing noise on a factory level, where the length of power lines and their complex network are very different from a sterile and predictable laboratory environment.

Sometimes, built-in EMI filters can amplify the noise signal in a factory environment rather than suppress it.

Figure 8 shows noise on power line amplified by a regular built-in EMI filter. This paper11 presents more details on this phenomenon

EEWeb | Electrical Engineering Community

Raw signal on power line After typical EMC filter

Figure 8: Noise Amplification from Regular EMI Filter

Raw signal on power line After OnFILTER CleanSweep® Filter

Figure 9: Reduction of Noise after specially-designed power line EMI filter

Suppression of noise on power lines in a factory environment requires special considerations which are very different from those required for regulatory compliance. This shows suppression of noise by a specially designed filter for such applications – OnFILTER’s CleanSweep power line filter AF series. As shown in Figure 9, the transient signals on power line are reduced to the point of insignificance.

Connecting an EMI filter is quite simple, as shown in Figure 10 – plug a filter into an electrical outlet and plug your equipment into the outlet on the filter. Now your equipment is protected against noise on power lines.

Visit www.eeweb.com

19

TECHNICAL ARTICLE

EMI Filter

To conclude, the use of power line EMI filters is the most costefficient and the most effective way of improving uptime by reducing EOS in production environment, reducing downtime and improving reliability of sensitive components.

References: 1. Intel Packaging Databook, Chapter 6 Intel, 2000 2. IPC-A-610-E, Acceptability of Electronic Assemblies, 2010 3. IPC-7711 Rework, Modification and Repair of Electronic Assemblies, 2003 4. Temperature Dependence of Electrical Overstress, Craig Hillman, PhD, DfR Solutions

Component Figure 10: Connection of CleanSweep® Power Line EMI Filter

There are two fundamental methodologies to consider. One is to reduce a generation of EOS-causing signals; another one – to prevent EOS signals reaching sensitive equipment and components. If you know the “culprits” that cause most of the noise in your environment, then the first approach may help.

However, because there can be

Receptacles, W. Farwell et.al., Raytheon Corporation.

Proceeds of 2005 EOS/ESD Symposium 10. EOS Exposure of Magnetic Heads and Assemblies in Automated Manufacturing 11. EOS Damage by Electrical Fast Transients on AC Power, A. Wallash, V. Kraz, Proceeds of EOS/ESD Symposium, 2010 12. CleanSweep AC Power Line EMI Filters, OnFILTER, Inc. http://www.onfilter.com About The Author Vladimir Kraz is a founder and a president of OnFILTER, Inc. Prior to founding OnFILTER he started and was a president of Credence Technologies, Inc., a manufacturer of ESD and EMI instrumentation, which was acquired by 3M. Mr. Kraz holds 22 U.S. Patents and is active in ESD Association’ and SEMI Standards activities. He has written a number of papers on the subject of ESD and EMI physics and management, many of which can be found at www.onfilter.com/ library.html ■

5. EMI Issues in the Manufacturing Environment, V. Kraz, Conformity Magazine, January 2007 6. Ground Bounce Basics and Best Practices, Phil King, Agilent Technologies 7. How Good Is Your Ground?, V. Kraz, P. Gagnon, Evaluation Engineering, May 2006 8. EOS Analysis of Soldering Iron Tip Voltage, Baumgartner, G.; Smith, J.S., Proceeds of EOS/ ESD Symposium, 1998 9. EOS from Soldering Irons Connected to Faulty 120VAC

EEWeb | Electrical Engineering Community

Visit www.eeweb.com

20

TECHNICAL ARTICLE

so many pieces of equipment in a single production environment and the difficulty in identifying noise sources, it is a much more practical approach to use EMI filters for noise-sensitive equipment as they will suppress noise regardless of its source. OnFILTER’s CleanSweep® EMI filters suppress noise in both direction, assuring that noise generated by filter-protected equipment itself won’t pollute the power network as well.

Get the Datasheet and Order Samples http://www.intersil.com

Low Power Ambient Light and Proximity Sensor with Internal IR-LED and Digital Output ISL29043

Features

The ISL29043 is an integrated ambient and infrared light-to-digital converter with a built-in IR LED and I2C Interface (SMBus Compatible). This device uses two independent ADCs for concurrently measuring ambient light and proximity in parallel. The flexible interrupt scheme is designed for minimal microcontroller utilization.

• Internal LED + Sensor = Complete Solution • Works Under All Light Sources Including Sunlight • Dual ADCs Measure ALS/Prox Concurrently • <1.0μA Supply Current When Powered Down • Temperature Compensated • Pb-Free (RoHS compliant)

For ambient light sensor (ALS) data conversions, an ADC converts photodiode current (with a light sensitivity range up to 2000 Lux) in 100ms per sample. The ADC rejects 50Hz/60Hz flicker noise caused by artificial light sources.

Intelligent and Flexible Interrupts • Independent ALS/Prox Interrupt Thresholds • Adjustable Interrupt Persistency - 1/4/8/16 Consecutive Triggers Required Before Interrupt

For proximity sensor (Prox) data conversions, the built-in driver turns on an internal infrared LED and the proximity sensor ADC converts the reflected IR intensity to digital. This ADC rejects ambient IR noise (such as sunlight) and has a 540μs conversion time.

Applications • Display and Keypad Dimming Adjustment and Proximity Sensing for: - Mobile Devices: Smart Phone, PDA, GPS - Computing Devices: Laptop PC, Netbook, Tablet PC - Consumer Devices: LCD-TV, Digital Picture Frame, Digital Camera - Industrial and Medical Light and Proximity Sensing

The ISL29043 provides low power operation of ALS and proximity sensing with a typical 136μA normal operation current (110μA for sensors and internal circuitry, ~28μA for LED) with 220mA current pulses for a net 100μs, repeating every 800ms (or under).

The ISL29043 uses both a hardware pin and software bits to indicate an interrupt event has occurred. An ALS interrupt is defined as a measurement that is outside a set window. A proximity interrupt is defined as a measurement over a threshold limit. The user may also require that both ALS/Prox interrupts occur at once, up to 16 times in a row before activating the interrupt pin.

Related Literature • See AN1436, “Proximity Sensors”

The ISL29043 is designed to operate from 2.25V to 3.63V over the -40°C to +85°C ambient temperature range. It is packaged in a clear, lead-free 10 Ld ODFN package.

255

VDD

VLED

C3 0.1µF

R3 10kΩ

VI2C PULL-UP

3V

DD

4 GND 5 REXT

8

INT 7 SDA 6 SCL

SLAVE_1 SDA SCL

I2C MASTER µCONTROLLER INT SDA SCL

SLAVE_0

1 LED+ LED- 10 C1 1.0µF 2 ADDR0 IRDR 9 C2 1µF

R2 10kΩ

I2C SLAVE_n SDA SCL

ISL29043 REXT 499kΩ

204

PROX COUNTS (8-BIT)

R1 10kΩ

110mA (18% GREY CARD) 220mA (18% GREY CARD)

153

110mA (WHITE COPY PAPER)

102

220mA (WHITE COPY PAPER) 51 0

0

25

50

75

100

125

150

DISTANCE (mm)

FIGURE 1. TYPICAL APPLICATION DIAGRAM

February 9, 2012 FN7935.0

FIGURE 2. PROXIMITY RESPONSE vs DISTANCE

Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2012 All Rights Reserved. All other trademarks mentioned are the property of their respective owners.

The Story of

Phil Golden Design Engineer

James Clark Maxwell

and Switched Capacitor Filters

T

he impact of switched capacitor filters on integrated filter design in the late 1970s was truly revolutionary, and is still considered one of the most significant inventions in the history of ICs [1].

Suddenly the painfully large time constants needed for low frequency signal processing were realizable in a very compact fashion, and in addition became trivially programmable via the clock frequency. The direct emulation of resistors enabled switched capacitor filter designers to utilize a wealth of design techniques that were already in use for active RC filters. This was the most critical attribute of the new technology because it enabled the veritable explosion of switched capacitor design activity in the late 70s and early 80s. Perhaps the most impressive feature of this new technology, however, was how beautifully it jibed with the CMOS technologies that would come to dominate analog design. Time constants could now depend on capacitive matching— still the most tightly controlled matching parameter of any analog component in a CMOS process. This didn’t just hold at nominal conditions either, these time constants were predictable over the process, temperate and voltage corners that were the scourge of active RC filter

EEWeb | Electrical Engineering Community

designers. Utilization of switches, capacitive matching, and digital clocks made switched capacitor circuits feel less like just a new idea, and more like destiny.

Sure, switched capacitor filters have some tricky aspects. The switching introduces aliasing of both the signal and anything that can interfere, including noise; approximations to continuous time filters have inaccuracies due to finite clock speed, and there are all sorts of switch non-idealities to contend with. Additionally, simulation of these filters required such additional overhead that new custom simulators were developed [5]. Nonetheless, it is clear from the sheer number of switched capacitor filter publications in the decade following 1978 that these issues were not proving to be too troublesome. Switched capacitor filters were about as sexy as it gets in the analog circuits world.

Given this state of affairs, it may seem somewhat odd that the core idea behind switched capacitor technology was invented a century before this eruption of publications— and it was published in one of the most famous scientific books of all time. So it is reasonable to assume that at least a few people read it.

Visit www.eeweb.com

22

TECHNICAL ARTICLE

Vin

R1

–

C2

C

+

TECHNICAL ARTICLE

R2

Vout

C

–

Vin C1

+

BW3db≈1/2πR2C

BW3db≈C2fclk /2πC

R2C product typically has +/–20% accuracy

C2 /C typically has +/–0.2% accuracy

Vout

Figure 1: How switched caps improve filter accuracy.

As such, the history of switched capacitors is one of the best illustrations imaginable of the general principle that innovation is the combination of creativity and value. In other words, to really make a splash, you need to not only have a great idea, but also to have people who want to use it [2].

In 1873, James Clark Maxwell published an idea explaining that he wanted to measure the value of a capacitor, or a ‘condenser’ as it was then often referred to, as a result of its ability to store a higher density of electrical charge than a typical conductor. On pages 374– 375 of ‘A Treatise on Electricity and Magnetism, Volume 2,’ [3] Maxwell describes connecting the capacitor to be measured in a circuit to charge it. He then quickly reverses the polarity of the capacitor connection using a commutating switch. Following this, he demonstrates that if this is repeated with a frequency of f, the average current flow will be equivalent to that of a resistor of value 1/(f.C). He uses the fact that he can measure resistance (using any of the methods described previously) to substitute in a resistor, measure it, and thus calculate the capacitance of the condenser. Here then, in one of the most celebrated technical volumes of all time, is the core idea of switched capacitors (i.e., emulating the average resistance of a continuous time resistor by switching a capacitor). It is laid out in black and white (actually black and sepia), with a clear accessible description and simple equations to better illustrate the principal. So why did it take almost exactly one hundred years for this idea to catch on?

EEWeb | Electrical Engineering Community

The simple reason, of course, is that not very many people were interested in determining condenser values, which was Maxwell’s stated value of the technique. It is probably a mistake to think that it was not considered to be a creative idea. The issue was much more likely that it simply was not considered much at all because people did not have a pressing need or use for it. Fast-forward to the 1970s and this is the fundamental change, because suddenly the world was calling for this technology. Incidentally, at this point it was effectively reinvented, being described as a ‘rather interesting and previously unrecognized’ concept in Fried’s seminal ‘Analog Sample-Data Filters’ IEEE Journal of Solid States Circuits paper in 1972 [4].

So what can this story teach us about how to innovate?

Here we have one of the most famous scientists of all time, writing in one of the most famous scientific books of all time, describing what would become one of the most revolutionary ideas in the history of analog circuits, and no one noticed. This reminds us that designers working in isolation from their potential customers may struggle to produce innovative products that really add value. And this holds even if they are really smart, and their ideas are good. This in turn suggests why one of the key challenges for many semiconductor companies is to connect a deep understanding of underlying market needs with internal technology capability. Neither is typically trivial to assess.

Visit www.eeweb.com

23

TECHNICAL ARTICLE

[2] J. Paap, “Using Competitive Technical Intelligence to Stimulate Innovation”, available at http://www.jaypaap. com [3] J. C. Maxwell, “A Treatise of Electricity and Magnetism”, Oxford Clarendon Press, 1873, vol. 2, pp 374-375

About the Author Phil Golden is a principal design engineer and project manager at Intersil Corporation, specializing in circuit design and signal processing. He was educated at Stanford University, where he was a graduate fellow from late 2003 until spring 2005, and the University of Dublin.

■

[4] D. Fried, “Analog Sampled Data Filters”, IEEE JSSC, August 1972 [5] K. Kundert, “Simulating Switched Capacitor Filters with SpectreRF”, available at http://www.designersguide.org/Analysis/sc-filters.pdf

EEWeb | Electrical Engineering Community

Visit www.eeweb.com

24

TECHNICAL ARTICLE

[1] B. Murmann, “Signal Conditioning Circuits”, Stanford University Course EE315a, available online at https://ccnet.stanford.edu/cgibin/course. cgi?cc=ee315a&action=handout_download&handout_ id=ID126954294624704

RETURN TO ZERO RETURN TO ZERO

EEWeb | Electrical Engineering Community

Visit www.eeweb.com

25

RETURN TO ZERO RETURN TO ZERO

EEWeb | Electrical Engineering Community

Visit www.eeweb.com

26