At 01:01 PM 12/17/01 -0500, Chris Loiacono wrote:
>All I'll say on the subject at this point is that tantalum caps are great
>when you are dealing with lots of noise in a digital circuit, when you just
>can't seem to decouple well enough with cheap ceramic discs. I don't care
>why, nor do I care how many more pennies they cost. They just make great
>decoupling caps.

If you look at what you're trying to decouple, you can do a better job,
rather than just shotgunning it.  Shotgunning can also induce problems.
(you have a 15 ohm resistor in series with the VCC supply, right)

Generally, smaller caps for higher frequencies.
It is also important that the PCB layout supports bypassing.
Layouts that have the cap from VCC on one chip to GND on another chip are
fatally broken.

I generally use a few zero ohm resistors to steer grounds, a few 1-10 ohm
resistors, a few 0.1 and/or 0.01uF caps, and that's about it.

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