> [mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Olin Lathrop
> Bruce Partridge wrote:
> > More information:
> >
> > I'm using a 16F819 and drawing 125 uA during sleep.  The regulator is
> > 50uA, and the only other component is the op amp which should be <5uA
> > when shutdown.  ADC, BOR, LVP, PWM are all shutdown.  All other pins
> > are outputs and are set to 0.
>
> What about the voltage divider for the battery voltage you
> mentioned before?

The voltage divider is a 59K and a 47K resistor running from the battery.

> We need to see a schematic.  There seems to be a lot you are not
> telling us.
>
> > VCC is tied to VREF+ at 4V.
>
> Vcc for what?  What is the PIC power tied to?

The regulator that is drawing 50uA.  VCC is for the PIC and the op amp.

Here it a better attempt at an explanation (maybe.)

The pic is powered by a 6V battery which goes through a 4 V voltage
regulator.  The regulator powers the PIC, an op amp, and an led.  The op
amp, led, and all other ports are off during sleep.

There are three pins coming into the ADC on the PIC that I would like
suggestions on how to handle during sleep.  One is from the voltage divider,
the second is from the powered down op amp output, and the third is the
output from the regulator which is being used as VREF.

Is there anything I can do to reduce the current this system uses during
sleep?

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