If you have 2 additional I/O lines on the PIC, use one to detect the
power failure and the other to switch on a LED ( to drain the cap) AFTER
you finish writing to the EEPROM.

Pailoor


Lynx {Glenn Jones} wrote:

> Hello all,
> I have a circuit (it contains a pic) which has a couple of rather
> large
> aluminum electrolytic capacitors (2200uF) as supply filters. the
> problem
> is that when the circuit is turned off, the charge takes a little
> while to
> dissipate (i have a power on led in series with a 1K resistor across
> the
> supply lines) and while its dissipating, the pic among other things is
>
> still funtioning. I am worred that the pic might end up in one of my
> routines which, for example writes to an I2C EEPROM, and corrupt the
> data
> there. so what i need is a way to disipate the capacitor reletively
> quickly after power down. I was thinking of putting a diode in paralel
> in
> the wrong direction (anode to gnd, cathode to vcc) but i dont think
> this
> will work, since the charge in the capacitor is polarized. I hope
> someone
> has an idea.. thanks agian
>
> --------------------------
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