How to Build a Potbox

Analog VLSI chip architectures require a special setup for chip testing. One can build dedicated circuit boards, but this is time-consuming and wasteful for prototype chips. Some signals are expected to be digital, but most are analog, and power supplies may be needed in a variety of configurations. Generally, numerous voltage biases are applied to the chip, requiring external voltage sources.

One solution for a quick and easy way to test prototype chips was the potbox, built by Lloyd Watts in Carver Mead's group at Caltech. The potbox is so named because of the array of pots (potentiometers) that provide bias voltages by tapping off the power supply.

I have written up plans for a slightly enhanced potbox, one which has been serving Dr. Godfrey's analog VLSI group at Stanford for the past several years. The design is written up here: Potbox paper.

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Last updated: October 11, 2005 at 11:42pm