I don't know about anybody else, but in ALL my standalone PIC projects I have used a standard 2 lead quartz crystal directly across the OSC in/out pins (15 & 16 - I only use 16C84 ) and never had a crystal fail yet.


-----Original Message-----
From:   John P. Leonard [SMTP:leonard@TARDIS.SVSU.EDU]
Sent:   Monday, May 18, 1998 2:41 PM
To:     PICLIST@MITVMA.MIT.EDU
Subject:        crystals

A while back (before the N-bomb stuff, but maybe after the cow stuff)
someone mentioned a problem with BURNING-OUT crystals by using the wrong
value resistors.  I'm using 3.58Mhz ceramic oscillators with 56pf caps on
a batch of 16C554's running at 3.3V from Ni-Cd batteries and NO resistors.
Could this cause premature failures?  The 16C554 data sheet diagram and
spec's don't include any limiting resistors for the oscillator circuit.
The chips are programmed as having "XT" oscillators.

I nominate Andy Warren as official spokesman for the PIC-list when the
wierd sh*t pops onto the list.  (Man, talk about fuzzy logic...)

John
(the BEST engineering student employee I've ever had was from Laos;
 probably the hardest working man I've ever met.)