Tim Wescott wrote:
Jim Wilkins wrote:

On Jul 22, 12:05 pm, Tim Wescott wrote:

...
Most integrated circuits aren't 'shimmed' so much as selected. ...
Tim Wescott


Devices that combine analog with digital often have calibration EPROMs
to adjust the gain and offset of A/D converters, for example.


Hmm. Good point. I was thinking of laser trimming and other gross
physical changes to the chips, which has gone seriously out of vogue.
But 'calibration' lives in the same conceptual space as 'shimming', I
suppose.

Don't believe it. Chips that have a lot of digital circuitry
already will have cal PROMs built in, but a LOT of high-end
op-amps, comparators, etc. are still laser trimmed to set the
offset to near zero.

Jon