At 10:20 31/05/99 +1000, you wrote:
>Hi,
>
>I need to protect my PIC16LF84 against reverse polarity. Currently I'm
>running the circuit of 2 x 1.5 N cells (2/3 AAA). I want to protect the
>circuitry from the batteries being inserted the wrong way.
>
>I'm not keen to put a diode in series with the batteries as I'll loose 0.6V.
>
>Thanks,
>
>Peter.
>---
>Peter Homann    Email:  peterh@adacel.com.au
>Adacel Technologies Ltd _/_/_/ _/_/_/ _/ Phone:   +61 3 9596 2991
>250 Bay St, Brighton   _/  _/   _/   _/  Fax:     +61 3 9596 2960
>Victoria  3186        _/_/_/   _/   _/   Home:    +61 3 9555 5603
>AUSTRALIA            _/  _/   _/   _/_/_/Mobile:      0414-494578
>------------------------------------------------------------------------
>
>

It depends on quite a few things, as to what can be done.
A shky diode in series will only give you 0.2V drop.
If the current is very low, then even a silicon diode will not give the
full 0.6V.
On a low current circuit a simple series resistor may suffice
A diode accross the battery pack may be better as a simple 1 Ampere shky
will do the job

Dennis