> Many chips, including probably the LM386, can be "powered down" by
> feeding DC into one of the audio inputs to bias the chip way out of the
> normal linear range.

That's a good idea. Even we old farts pick up bits'n'pieces from this
list.

Nobody has mentioned the number one gotcha for powering down bits of
circuits.
Always check that there aren't any inputs with protection diodes or
other internal circuitry that is going to try and power the rest of
the circuit up through a pin. I don't know how many times I've seen
whole boards powered off a single CMOS output when they are
supposed to be in "power down".

Steve.

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Steve Baldwin                Electronic Product Design
TLA Microsystems Ltd         Microcontroller Specialists
PO Box 15-680, New Lynn      http://tla.co.nz
Auckland, New Zealand        ph  +64 9 820-2221
email: steveb@tla.co.nz      fax +64 9 820-1929
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