I use the simpler cct from the same spec sheet page with resistors
only and it works very well.

The Zener cct should work as shown - is your transistor an NPN or a
pnp ? :-)



Russell McMahon


From: John Duncan
>I am building a project with a 16F84 and thought it would be a good
idea to
>incorporate a brownout circuit to reset the part in the event of a
>brownout.  I want to use the circuit featured in the spec sheet for
the
>16C84 with a zener diode and a PNP transistor and a few resistors.
I have
>a lot of BC328 sitting about so I thought that I would use a few.
Trouble
>is that the circuit does not work for me.  Vdd is 5 volts I am using
a 3.3V
>zener.  I thought that the transistor would trigger when Vdd got to
4V, but
>/MCLR does not go low till Vdd is approx 2V.  Has anyone had success
with
>this circuit and point me in the right direction.