Page 157 - The Art and Science of Analog Circuit Design

Jim Williams

11. Tripping the Light Fantastic

Introduction

Where do good circuits come from, and what is a good circuit? Do they
only arrive as lightning bolts in the minds of a privileged few? Are they
synthesized, or derived after careful analysis? Do they simply evolve?
What is the role of skill? Of experience? Of luck? I can't answer these
weighty questions, but I do know how the best circuit I ever designed
came to be.
What is a good circuit, anyway? Again, that's a fairly difficult question,
but I can suggest a few guidelines. Its appearance should be fundamen-
tally simple, although it may embody complex and powerful theoretical
elements and interactions. That, to me, is the essence of elegance. The
circuit should also be widely utilized. An important measure of a circuit's
value is if lots of people use it, and are satisfied after they have done so.
Finally, the circuit should also generate substantial revenue. The last time
I checked, they still charge money at the grocery store. My employer is
similarly faithful about paying me, and, in both cases, it's my obligation
to hold up my end of the bargain.
So, those are my thoughts on good circuits, but I never addressed the
statement at the end of the first paragraph. How did my best circuit come
to be? That's a long story. Here it is.

Towards the end of 19911 was in a rut. I had finished a large high-speed
amplifier project in August, It had required a year of constant, intense, and
sometimes ferocious effort right up to its conclusion. Then it was over,
and I suddenly had nothing to do. I have found myself abruptly discon-
nected from an absorbing task before, and the result is always the same.
I go into this funky kind of rut, and wonder if I'll ever find anything else
interesting to do, and if I'm even capable of doing anything anymore.

Portions of this text have appeared in the January 6,1994 issue of EDN magazine and publica-
tions of Linear Technology Corporation. They are used here with permission.

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