Why Bob Pease complained about Dr. Middlebrook’s book

A book about differential amplifiers before EDA tool age

Robert (Bob) Peace was a well-known, highly respected analog circuit design guru, a colleague of James Williams, and who died in a car crash after attending James’ memorial service. What a tragic story. Not the story to tell in this article though.

Now who is Dr. Middlebrook.

Dr. Middlebrook was a professor and a genius who taught analog circuit design at CalTech. He pioneered design oriented analysis (D-OA) and came up with lots of math techniques to make circuit design more intuitive.

He is relatively less well-known, but still highly respected in power electronics community.

One day, I came across Bob Peace’s column, called “What’s all this error budget stuff, anyhow?”(first appeared in Electronics Design Magazine, 6/8/2006). In that piece, Bob complained about a certain Dr. Middlebrook’s differential amplifier book, being full of partial differential equations, and not friendly to young, green engineers.

Now since you have known both of these characters, wouldn’t it surprise you that Bob didn’t like Dr. Middlebrook’s book? I was shocked.

It happens many times that an experienced analog circuit design engineer with very much practical knowledge bashing an academic professor for being too math-full, or certain academic circuit paper being impractical and useless. But that shouldn’t happen to Dr. Middlebook’s book.

Because the late professor Middlebrook is probably the first few academics to realize the gap between engineering school graduates and real engineers at the job. The difference between given a circuit to analyze and given a specification to come up with a circuit design is huge, and school courses aren’t helping to bridge the gap.

That’s why professor Middlebrook pushed very hard for D-OA, which embodies low entropy math expression that can be used “backwards” for circuit design, approximations that simplify mathematics to solve the circuit problem more “intuitively”, the list goes on and on. He is on our engineers’ side, fighting what he called “math paralysis”.

So why Bob, a most practical electrical engineer, didn’t seem to like our beloved Dr. Middlebrook’s book that is titled “differential amplifiers” published in 1962.

Here is the link to read that 1962 differential amplifier book for yourself. (I got a used paper copy from Amazon as well.)

At first glance, there are pages and pages of math equations in this only 86-page book, just like Bob said.

However in the subsequent articles, I’d like to answer three questions:

  1. Why the math becomes so complicated analyzing differential amplifiers?
  2. Are these math equations in low entropy form, and can be used for circuit design?
  3. Would the “sequential analysis” method, used in that book, be of any value to today’s circuit engineers who mostly rely on EDA simulation tools to design circuits.
  4. Was Bob’s comment that the book being too math-full fair or not.

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