Microwave Journal
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Barrie Gilbert

Living and Learning with Barrie Gilbert

February 4, 2020

Barrie Gilbert was unconventional.

For those who might have attended one of his standing-room-only performances at panel sessions or read his science-fiction blogs, featuring a curious young designer, or learned from one of his many short course lectures, you know what I mean. Perhaps, you have heard stories of mythical proportions from others. In any case, those are just a few facets of this remarkable man.

For those few of us who worked closely with him for many years at Analog Devices’ Northwest Labs, he represented much more. He could be a philosopher, an expert, a mentor, a team member, a critic and an advocate, all in a single day. While he is best known for the Gilbert cell mixer, the Translinear Principle and his unwavering dedication to the bipolar transistor, there is so much more to Barrie. I would like to share a few examples that capture the Barrie Gilbert who only we knew.

Full disclosure: Barrie hired me 20+ years ago and gave me the opportunity to run “his” design center. What a privilege it has been to have Barrie in my career all these years.

Analog Devices’ founder, first CEO and chairman of the board, Ray Stata, famously said that our success was based on the premise of hiring great people and then getting out of their way. No one epitomized this philosophy more than Barrie, who was hired by Ray in 1972, following his years at Tektronix in Beaverton, Oregon. In 1979, Barrie founded the Northwest Labs, ADI’s first remote site — before the age of computers, internet, telecons and email. He loved the Pacific Northwest that reminded him of his native home in England, but with mountains.

Rules are for Insects

Barrie despised arbitrary constraints, whether they be schedules, the infamous voice of the customers or circuit topologies.

Many marketing directors struggled to control and direct Barrie’s efforts. A laundry list of pre-defined specifications accompanied by demands to stay within its scope would be unceremoniously tossed into the trash bin and replaced with a complete self-inspired data sheet.

Those who could appreciate his insights and trust in his instincts were more often than not rewarded with years of high margin revenues. Barrie’s total product revenues are estimated to be >$2 billion, primarily from products that he defined and designed “despite marketing.”

Make Transistors Dance

Barrie was not a fan of standard circuit cells. He was the ultimate tinkerer, which, according to Barrie, originated in his post-World War II youth with surplus electronics. He saw analog circuits as living beings, prone to mutations and individuality.

Barrie had a passion for classical music and, much like the instrumentation of symphonic pieces, he crafted each sub-circuit for its job, working holistically and in concert with its sister sub-circuits. In many cases, the next product was an opportunity to try out one of many new bandgap bias cells or transconductors or output stages he was “inventing.”

It was sheer pleasure to gather around his impromptu white-board discussions as he took us on a what if? journey along his thought process from the creation of a brand new topology through its refinements and embellishments.

The office walls ran out of room for his 100 or so patent awards. I can personally attest that there were many more clever inventions that the patent lawyers never got around to. It seemed so simple when he did it — but suddenly became incredibly liberating to explore the wealth of topologies possible with only a handful of transistors!

Start at the End

Before Barrie ever placed one transistor on a schematic, he had already deliberated the package pin-out, the detailed specifications, the block diagram, the multiple customer application circuits, etc.

He had a sense of balance and aesthetics. Barrie’s inception of the product down to the proposed chip layout were deliberate works of art. Clarity of purpose guided design choices and exposed potential issues early on. He had an uncanny ability to anticipate what the customer would want, even if he or she had no idea yet.

At one notable internal planning meeting for the following year’s products, we were all asked to bring our proposals for review with the marketing and product support teams. Barrie volunteered to go first and proceeded to show 70 slides (with animation) on his new variable gain amplifier and the 20 unique ways it could be configured for different applications. I sheepishly followed with an unimaginative one-pager. I quickly learned that product design is much more than circuit design.

Good with the Fundamentals

For all the sophistication of his circuits, Barrie was not a believer in complex equations. His foundation design philosophy proposed a balance between simple models with layered complexity and thoughtful simulation, in order to develop intuition and insight.

“If your circuit does not work as expected with the simplest of models, it certainly won’t get better with non-idealities added.”

He strongly articulated for concept re-use rather than cell re-use, fearing their unintentional misuse and abuse. I learned early on not to take one of Barrie’s magical cells and simply drop them into my design without fully understanding its operation.

Over time, we, as a group, communicated our concepts using recurring icons or memes that captured the essence of our ideas: crossed arms represented the bandgap principle of PTAT (proportional to absolute temperature) and CTAT (complementary to absolute temperature) components.

To this day, our search for new talent prioritizes strong fundamentals over a collection of facts: the WHY rather than the WHAT.

Life after Barrie

Barrie and I had many conversations over the years, ranging from op-amp compensation to cosmology to the quantum nature of noise and beyond.

The wider design community and Analog Devices have lost a true icon of the industry for over 50 years. His family has lost a husband, father and grandfather. I have lost a mentor, colleague, manager, idol, sounding board and dear friend, to whom I owe so much. He has left a great technical legacy, the many young designers he inspired and especially our band of innovators at the Northwest Labs.

We all know that he spent every day of his adult life doing the kind of work he loved most: inventing and refining.

Rest in Peace