Mar 24, 2017

Ides of March in The House of Bob Swanson

It was March 15, 2017. I spent a few hours with Bob Swanson on his last day as Executive Chairman of the company he founded with Bob Dobkin over 35 years ago, Linear Technology Corporation. A few days earlier, the legal transaction concluded with Analog Devices acquiring the company. Bob had packed up what he wanted from his office and graciously let me sort through the rest and keep it for historical purposes. As I work through it, I will post more articles here.

Bob confessed that he is a bit of a pack rat. There were documents from 1981 about the initial incorporation of the company. The first documents were filed before the founders had decided on a name for the company, so it was referred to as “THOBS” which meant “The House of Bob Swanson.” He would later say that he liked that title, but the other founders didn’t so they settled on Linear Technology. And that is very fitting. For LTC was created by Bob Swanson but also very much by the other founders - it was never about him, but he was a relentless driving force and steered it on a very deliberate, unwavering course. Yet he gave so much freedom to the brilliant technical people that created the products, built the products and supported the products. The face of the company would be the “IC design gurus”. Bob was the heart.

(I photographed this out of a book, which was obviously a poor photocopy. I need to find the original. I could write paragraphs on this photo - who is standing where, who is missing, who isn't wearing a tie.)

Next to the leatherbound copies of the incorporation documents and the initial public offering documents, was a full set of Linear Technology data books. The world has since gone digital, but in 2004 we printed the last full set of these books. Bob didn’t use them, but he liked to look at them. It was a visual representation of all the products we had created. It’s impressive.


As I shuffled through file folders, employees came in to say thanks to Bob. Scattered around the office were many items from customers, employees and professional organizations expressing thanks. Bob kept them. There are small note cards from employees that he still has. There are framed articles that featured Bob, tucked away. He didn’t display those but rather a mix of quotes, architectural drawings of Linear Technology buildings and framed mementos of the IPO. It wasn’t about Bob, but it was the house of Bob Swanson.

I had Bob sign his copy of Jim Collins’ book “Good to Great”. He quoted that book to employees over the years and Bob’s copy is dog-eared and highlighted. Collins also wrote “Built to Last” and both represent the way Bob ran Linear Technology.

He had a photo on his desk of his first Porsche. He mentioned what a good car it was; he always like Porsches. His son has that a first red car now and has restored it. It runs great; built to last. I need to ask him if that red Porsche in the architect’s rendering was meant to be his.

March 15 - the ides of March - is just another day. There was no betrayal. There is no animosity or sense of relief, either. This isn’t necessarily the way Bob wanted it to end; he would have preferred it to continue on as an independent company forever - it was built to last. He may not come into this office anymore, but his presence will always be felt. The sign out front now says Analog Devices, but it is also the house of Bob Swanson.

Feb 23, 2017

A CMOS Op Amp Story - Part 1

The quintessential analog component is the operational amplifier. And the overwhelming majority of modern integrated circuits are made on CMOS processes of ever-shrinking geometry. But early on, the “low and slow” use of MOS transistors in an analog circuit was ridiculed. “Complementary” was, well, not complimentary. So, how did we get to the CMOS op amp? And how would the Vegas strip and TV test patterns play a part in the story? Read on!
Wikipedia says that Frank Wanlass patented CMOS in 1963 while at Fairchild. It doesn’t say he invented it. Much like Alexander Graham Bell in 1876, he got to the patent office first. Coincidentally, also in 1876, W. G. Adams and R. E. Day published a paper in the Proceedings of the Royal Society entitled, “The action of light on Selenium.” It was the first observation of surface effects and described what we know of as the field effect transistor.
The footsteps for this story go back and forth between RCA on the east coast, Silicon Valley on the west coast and Utah, of all places.
Why Utah? I’ll save that for “part 2” of the story. As well as the Silicon Valley folks.
Why RCA?
Briefly, during World War I, the U.S. government commandeered all the radio companies and their patents for the war effort. After the war, they cut a deal with General Electric to take the assets from the American Marconi company and create the Radio Corporation of America (RCA) as well as the National Broadcast Company (NBC). Also part of the patent pool were GE, AT&T, Westinghouse and the United Fruit Company (yes, bananas). RCA bought the company that made the Victrola and moved into television in the 1930s. The TV tube research and development complemented their vacuum tube development in support of their own end-to-end television business. RCA Laboratories (similar, but not as famous as Bell Laboratories) was set up in Princeton, NJ. RCA was second only to Bell Labs in the number of transistor related patents during the 1940s and 1950s, indicating a strong commitment to basic semiconductor research.
Sarnoff set an ambitious vision for RCA and the lab, part of which included transistors. At RCA, Jerome Kurshan replicated the Bell Labs point contact transistor less than a month after their announcement. (Second place.) Prior to the consent decree, RCA tried to design around the Bell patents and by 1952 had solved the production issues for point-contact transistors. Under Kurshan’s guidance, George Sziklai developed “complementary” circuits in the early 1950s with H. C. Lin, long before MOS or even integrated circuits - but well after the 1876 (Adams and Day) or 1925 (Lilianfeld) “field effect” disclosures. J. Torkel Wallmark started a project assembling several amplifiers, switches and passives to make a prototype digital logic device in 1957 - but Kilby had his “integrated circuit” working first. Nobody remembers who came in second. No matter how you look at it, RCA made a blunder by not putting “complementary” and “MOS” together. Wanlass got the patent first, but Fairchild did nothing with it for several years. For the record, in 1960 Karl Zaininger and Charles Meuller fabricated a MOS transistor at RCA and then Fred Heiman and Steven Hofstein followed in 1962 with an experimental 16-transistor CMOS device at RCA. (Arguably first, but forgotten.) But it would be many years before all of the stability and production problems were resolved. So, at this point, RCA was in the lead - but CMOS was not yet practical.
As with the whole industry at that time, government contracts for the military and space programs funded and directed much of the development. Almost everyone felt that CMOS was too difficult and had too small of a market. Bipolar logic ruled. Straight NMOS dominated elsewhere. Even RCA wanted to focus elsewhere. But, Air Force contracts forced RCA to continue efforts on CMOS despite their problems and internal hostility toward it.
George Rotsky wrote a nice piece for EETimes about the struggle with making CMOS, most of which is probably true. I’ll paraphrase. In 1959, Steven Hofstein and Frederic Heiman joined RCA's David Sarnoff Research Center as part of a work/study program with Princeton. The group leader of the Electron Devices Research Laboratory, Tom Stanley, offered a choice.
"Follow everyone who are working on the junction field-effect transistor that Shockley invented in 1952. If you accomplish anything, you will end up working as a technician for some senior engineer. Or, work on the MOS transistor which everyone says will never work. There are problems with surface states, a problem Bardeen uncovered at Bell Labs. If you succeed, you'll be a hero. If you fail, so what?"
The initial focus was to find a better way to clean the silicon before growing the oxide. There seemed to be a million cleaning recipes, Hofstein recalls, none of which did any good. He then remembered that, to improve surfaces, metallurgists annealed metals in a hydrogen atmosphere. He tried it. Success! It was an exhilarating moment. Instead of cleaning the silicon before oxidizing, the trick was to anneal after oxidizing. Hofstein and Heiman were in inventor's heaven. Unfortunately, the MOS transistors weren't stable.
Meanwhile, Fairchild had discovered that sodium makes silicon unstable, but didn't know how to overcome surface states.
Along about 1965, Hofstein, with the blessings of the IEEE, organized the Silicon Interface Specialist Conference. He chose Las Vegas for the location, unknowingly sowing the seed for Las Vegas becoming a major site for technical conferences.
Rotsky paints this scene: Hofstein and Andy Grove are in the Stardust swimming pool, possibly chatting about the weather and the Las Vegas ladies. The conversation may have shifted to MOS transistors. Grove may have said that Fairchild had spent more than a million dollars tackling the surface-state problem. And Hofstein may have said that RCA had spent a similar sum on the instability problem. No one knows if or what was said in the pool, but it's possible that Hofstein said, "hydrogen," and Grove said, "sodium." Two million dollars and two words. Within a few weeks, the industry benefited from two good sources of MOS field-effect transistors and, not much later, from a growing industry that made larger and larger MOS ICs.
The Air Force computer system used RCA CMOS logic and memory circuits in 1965. In 1968, RCA introduced their CD4000 series logic family. Finally, they were first! Although they were a commercial success, it did not endure. In addition to government contracts, RCA’s solid state developments were disproportionately focused on television. As early as 1952, RCA had a prototype all-electronic television. And it was only in the late 1950s that RCA entered the merchant semiconductor market, prior to that it was all internal consumption for television and military contracts.
My research into CMOS pointed in several directions: CMOS logic, CMOS memories and CMOS image sensors. And these paths crossed from time to time. RCA, for example, invented the TFT (Paul Weimer, 1961) and did a lot of development of CMOS image sensors. They built the first solid-state camera in 1967 (prior to Bell Labs’ CCD Picturephone, remember that?). Image quality has always been important to RCA even way back in the tube era. I got sidetracked into researching an engineer named Otto Schade. Schade was born in Germany and came to the United States in 1926. He joined the Tube Division of RCA in New Jersey in 1931. His first widely recognized achievement was in 1936 on the electron optics behind the 6L6 beam power tube. He was a brilliant and prolific engineer, most noted for his work on the Modulation Transfer Function (MTF) - a well-known and widely used metric to characterize the resolution of almost any optical or display component as well as the resolution of overall imaging systems. This metric is used to characterize the entire display system as well as the performance of each individual system component from the camera lens to the human eye. This manifested itself in Schade’s high resolution test pattern.  In the course of his career, Otto Schade presented or published more than 30 papers and received 85 patents. He spent the rest of his career at RCA.

Unlike modern Silicon Valley, not only did engineers of that era spend their entire careers at one company but often their children joined the same company. And this was the case for his son. According to an interview with the Society of Information Display, sometimes Otto, Jr., had to cancel dates to serve as the test audience for his father’s lectures, and the planned building of a model-train layout in the cellar was scrapped in favor of a home darkroom to further study image quality. Few sons in history have been told by their father: “Sit down, I want to get the sine-wave response of your eye.”
Turns out, Otto, Jr., also had an impressive career at RCA with many, many patents. And some of his work involved CMOS analog!
I had the pleasure of talking to Otto Schade, Jr., on the phone. He said he joined the Solid State division (semiconductor division) in 1966, coming over from the “tube” division where he had been working on broadcast TV tubes. At the time, the digital group (developing the CD4000 family of digital logic devices) and the analog group were separated. He said, “the analog guys talked to the logic guys as seldomly as possible.” Otto, Jr., was constantly compared to his father and it made things difficult at times. Within the Solid State division, he struggled because his background was in mechanical and tube technologies, not semiconductors. He said, “It wasn’t much fun; there was so damn much learning to do.”
Otto gives much credit to Murray Polinsky for developing the analog version of the CMOS process. The process used by the CD4000 logic family was prone to ESD damage. The analog process developed by Polinsky included the necessary clamps and protection circuits to help these devices survive. RCA is not very well known as a semiconductor company, not even in those days. And the “RCA Review” probably didn’t reach as many people as the Bell Labs Technical Journal but there is a lot of good reading in there. But in that spirit, they tried to spread the information as much as possible. Otto had attended many ISSCC conferences and had attended some of the after-hours sessions where competitors would freely talk about the latest technology. They would say, “Turn off your recording devices and let’s just talk.” Even though he was well aware of Bob Widlar, Bob Dobkin, Dave Fullagar and many others, he didn’t really know them. They still felt isolated back in New Jersey.
Otto was working for Dick Sanquini (group leader, linear integrated circuit development) and the Vice President of the division was Bernie Vonderschmitt. In those days, management was able to talk to the engineers; they had their respect because they had also been engineers. Bypassing the normal organization because he knew Otto, Sr., Bernie asked Jr., “Can’t we make a circuit that has both bipolar and CMOS on one chip?” Schade’s team built a FET-input, 10V op amp with a CMOS output stage. And with that, we have the birth of the CA3130, arguably the first “CMOS op amp”.
That first op amp development was like the old saying, “a camel is a horse designed by a committee”. Technically, there are bipolar transistors in the chip, but perhaps that’s splitting hairs. It was introduced in 1974 and marketed as a CMOS op amp for use in predominantly CMOS systems. It would be several years before anything like it hit the market. I have yet to find anything particularly interesting about the CA3130 or its design but you can still buy them. It was reasonably popular in its day but not particularly precise.
I asked Bob Dobkin about the CA3130. He said it was really useful in “Ideas for Design” - as a noise generator! Coincidentally, I’ll remind you that Dobkin once considered joining General Electric to start up their integrated circuit group. He would have inherited this part.
Bob Pease made a vague claim to a CMOS op amp design in this same timeframe, albeit as part of a larger IC. From April 1999, “What’s All This CD4007 Stuff, Anyhow?”:
“I am slow, dumb, STUPIDO. However, the sudden cessation of stupidity is worthy of some mention. I knew about CMOS circuits in the 1970s. I even designed a CMOS operational amplifier back in '74. It used about 15 transistors to run on ±5-V supplies and provide a gain of 10,000. At the time, several engineers looked at my two-stage, cascoded differential amplifier and asked, ‘Why do you make life so complicated? Why don't you just use TWO transistors of a CMOS inverter for an op amp, like everybody else does?’ … This op amp went into the Teledyne Semiconductor 9400 analog to-digital converter with 8-, 10-, or 12-bit resolution.”And Pease also suggested: “If you want to read about an analog CMOS circuit, you should obviously read AN-88 in NSC's CMOS Databook. (Hey, don't waste your time. It mostly tells you how you can use a 74C04 as an op amp.)”

In 1986, RCA Solid State was acquired by General Electric and Jack Welch. The combined RCA/GE Solid State division was sold off to Harris Semiconductor in 1988 and combined with the original Intersil which they had acquired at about the same time. Otto noted that the lab in Princeton, NJ, (RCA Laboratories) was transferred to Stanford Research International, so they became “SRI East”.
Name Dropping
Dr. H. C. “Jimmy” Lin worked at RCA in the late 1940s and 1050s, working on linear applications with discrete bipolar transistors. He would be instrumental in the development of integrated circuits at RCA and, later, Westinghouse. He is referenced many times by Bob Widlar and most other great analog designers of the 1960s… on the shoulders of giants.
Dick Sanquini worked at National Semiconductor, initially as vice president of microprocessors, microcontrollers, and peripherals with subsequent roles as senior vice president of the consumer and commercial division and as the company's chief technology officer. Mr. Sanquini's career began in 1959 at RCA's Solid State Electronics Division, where he designed the company's first commercially available integrated circuits, and eventually served as general manager and director of memories and microprocessors. Mr. Sanquini holds a BSEE degree from the Milwaukee School of Engineering, Wisconsin.
Bernie Vonderschmitt worked at RCA for 34 years and was involved in an early industry rivalry over the design of color television. In 1953, Mr. Vonderschmitt was picked to head the development of a color television project at the company. Mr. Vonderschmitt headed the RCA solid-state division from 1972 to 1979. At that point, he moved to Silicon Valley to lead the component division of Zilog. At the age of 60, Vonderschmitt and two partners founded Xilinx.
Robert S. Pepper, Ph.D., served as a Vice President and General Manager of the Solid State division of RCA Corporation from 1979 to 1984. He had spent over 15 years in the semiconductor industry, notably as a Vice President and General Manager of the Semiconductor division at Analog Devices, Inc. Dr. Pepper joined Level One Communications in 1986 as the Chief Executive Officer and President. Dr. Pepper holds a BSEE, MSEE, and Ph.D. in Electrical Engineering from the University of California at Berkeley.

NOTES
Wikipedia
Phone call with Otto Schade, Jr, November 11, 2016.
“Otto Schade – A Pioneer with an Insight into Image Quality” Society of Information Society, staff article, http://informationdisplay.org/IDArchive/2006/January/OttoSchadeAPioneerwithanInsightintoImage.aspx

“Current Sources and Voltage References: A Design Reference for Electronics” By Linden T. Harrison

“What's All This CD4007 Stuff, Anyhow?” by Bob Pease, Electronic Design, Apr 5, 1999 http://electronicdesign.com/analog/whats-all-cd4007-stuff-anyhow


Jan 18, 2017

Tennis and Transistors – A Story of Dr. H. C. Lin

Dr. Hung Chang Lin is referenced in many analog circuit patents and papers for several ideas: single-diode compensation for temperature stabilization in bipolar transistors, the use of a diode-connected transistor instead of an actual diode to improve matching, and the invention of lateral transistors. The audio community also references him for the so-called “quasi-complementary” output design, and later for “active noise cancellation.” He was a creative, energetic scientist at a key time in the early days of transistors and integrated circuits. He spent 20 years as a scientist, and 21 as a professor at the University of Maryland.
I was curious about his footsteps – where did he go to school, where did he work and what other analog greats had he crossed paths with? It wasn’t MIT, Stanford or Fairchild. Instead, biographers cite his BSEE from Chiao Tung University (Shanghai) in 1941, MSEE from the University of Michigan in 1948 and a PhD from the Polytechnic Institute of Brooklyn in 1956 (now part of NYU).
Hung Chang Lin was born in Shanghai in 1919, the son of Dr. Dao-Yang – the former president of Chung Chi College in Hong Kong. This was during the warlord period following the fall of the Qing Dynasty. The Kuomintang (KMT) enlisted help from the Soviet Union to defeat the warlords and unite the country, starting in northern China. The Soviet Union created the Communist Party of China (CPC) sowing the seeds of Civil War that would reach Shanghai by 1927 and drag on for ten years. The period from 1937 to 1945 was the Second Sino-Japanese War, the latter part of which coincided with World War II making China an ally of the United States against Japan. Somehow among all this, Lin attended Chiao Tung University on a tennis scholarship and studied electrical engineering. In those days, “electrical engineering” meant communications and utility power distribution. Chiao Tung University was modeled in many ways after American Universities and brought in American professors. It was encouraged for graduating students to travel to America for post-graduate education and work experience – sponsored at times by the government – and return to China later. It is quite likely that Lin was acquainted with An Wang, the founder of Wang Computers. Wang graduated a year prior to Lin, stayed another year to teach and then worked at China Central Radio Works before coming to America.
By 1937, Japan occupied Shanghai. Many of the students and faculty relocated to the French Concession, an area adjacent to Shanghai owned by the French until 1943. As the war continued, the university offered scholarships to maintain enrollment. In 1940, a state-run branch of the school was set up in Chongqing, the provisional capital of Chiang Kai-shek’s Nationalist government. Lin graduated before the occupying forces took over the Shanghai school in 1942. From there he worked as an engineer for the Central Radio Works in Kweilin and then the Central Broadcasting Administration in Kunmin, far to the southeast of Shanghai. There was a strong feeling of patriotism with many students joining the army and others serving technical roles. It is estimated that between 1 and 3.5 million Chinese died during the war. Wang lost his parents and a sister. In Wang’s autobiography, he said, “Confidence is sometimes rooted in the unpleasant, harsh aspects of life, and not in warmth and safety. It is an intangible quality but it has its own momentum. The longer you are able to survive and succeed, the better you are able to further survive and succeed.”
Lin moved to the United States in 1947, receiving his MSEE from the University of Michigan in 1948. This was shortly after Bell Laboratories had announced the invention of the transistor. The Radio Corporation of America (RCA) offered Lin a position in their patent department. RCA was eager to catch up with Bell Labs and quickly replicated their point contact transistor. In the early days of the transistor, RCA was second only to Bell Labs (Western Electric) in the number of transistor related patents. After working in the RCA patent office for two years, Lin moved to the Industry Service Laboratories group (RCA ISL) which had been formed to teach people how to use that patents they were licensing. This involved writing reports or visiting licensees to support the patent information. This was in contrast to the frustration felt by Bell/Western Electric licensees who were flooded with theory but little practical help to manufacture and utilize transistors.
For the 1952 ISL Symposium held at the RCA Labs in Princeton, NJ, Lin wanted to present something other than the transistor radios his colleagues were developing. He created a roving microphone and an audio amplifier. He also created a wireless, musical keyboard. Of his temperature compensation patent, he said,
“If I did make any contributions to early transistor technology, then my study of the temperature effect was one. In the early days, when we tried to bias transistors in the same way as was done for a vacuum tube, it wouldn’t work. You see, the heater for the tube keeps the internal temperature pretty constant, but in the transistor, the temperature depends on the ambient temperature, which can vary widely.”
 “I built a 20 watt amplifier and took it to my boss to demonstrate, and took it outside where it was cold – it wouldn’t work. Another time, it overheated in use, and wouldn’t work. On the original 20 watt, I played music through a loudspeaker. I only needed one amplifier for monaural, because stereo was just coming out then. That amplifier really was one of my favorite circuits, because I used the so-called “Quasi- Complementary” design. I got a patent on this design and it is widely used today. You see at that time, we only had PNP (power) transistors, and these were all germanium. George Sziklai had just patented the complementary symmetry circuit (using both NPN and PNP), but we couldn’t get any good NPN (power) transistors, so that is why I developed the quasi-complementary.”
(Photo credit: Lin family photo)
Lin completed his PhD in Electrical Engineering from Polytechnic Institute of Brooklyn in 1956 while his wife, Anchen, worked to support them. That same year, he joined his friend Dr. Chu at Columbia Broadcasting Systems (CBS). CBS was a broadcasting company that wanted manufacturing capability and therefore had just acquired Hytron, a maker of TV tubes. This quickly progressed to semiconductors and Lin was hired to manage their applications group. Their biggest merchant business was power transistors for audio amplifiers in car radios. CBS ultimately divested this group in the 1960s.
George Sziklai joined Westinghouse and convinced them to hire Lin to work on integrated circuits in 1959. Lin recalled that in those days, anyone working on integrated circuits was considered a “laughing stock” by most of the industry. Westinghouse was heavily involved in military contracts and Lin was not immediately told the nature of his projects. In 1962, Autonetics was instrumental in forcing Westinghouse to abandon their mesa technology and develop a planar process similar to Fairchild’s. As part of the Minuteman II missile project in 1963, Westinghouse developed a differential amplifier. Texas Instruments, the other contractor, used a 4-layer PNPN process but this consistently failed radiation testing. This is when Lin came up with that lateral PNP which could be produced alongside an NPN transistor without any changes in processing or additional masking steps. Harry Knowles, Lin’s boss and a recent arrival from Motorola, bet Lin $5 that it wouldn’t work. Lin won. This is still widely used in analog integrated circuits, today.
Roughly parallel to all this, alumni of Chiao Tung University in New York helped resurrect the school in Hsinchu, Taiwan, officially established in 1958 as the National Chiao Tung University (NCTU). Initially, the only courses were in the Institute of Electronics. Lin and many others would support as visiting professors, conducting research and heading development projects. The establishment of the Semiconductor Lab in 1964 is considered the foundation of Taiwan’s semiconductor foundry industry. From the outset, the decision was made to focus on CMOS and to cooperate with RCA as its development partner. Dr. Lin was instrumental in fabricating NCTU’s first IC in 1966.
In 1969, Dr. “Jimmy” Lin joined the University of Maryland as a full-time professor where he only missed one class in the next 21 years. After his retirement in 1990, he continued to mentor students as Professor Emeritus. He held more than 60 patents, wrote the 1967 textbook “Integrated Circuits” and co-authored three others. He was elected a fellow of the IEEE and inducted into the Innovation Hall of Fame at the University of Maryland’s Clark School of Engineering. He was generous with his time and always remembered his fatherland. The Jimmy H. C. Lin Graduate Scholarship for Entrepreneurship supports graduate student applying from his Alma Mater, the Chiao Tung University in Taiwan and the (renamed) Jiao Tong University campuses in Shanghai and Xian.
And apparently, he was an avid tennis player until he was 90.

NOTES
Many thanks to the University of Maryland

“Made by Taiwan: Booming in the Information Technology Era” edited by Chun-Yen Chang, Po-Lung Yu

Digitized copy of the 1964 Reunion Record, published by the Chiao Tung Alumni Association
“History of Semiconductor Engineering” Bo Lojek

A Chinese-American Exciting Journey Into the 21st Century”, K. P. Wang