Hi, Spehro.

HC49U type, although there is a discrepancy between my crystal labels and
Raltron's data sheet, as mentioned before...


----- Original Message -----
From: "Spehro Pefhany" <speff@INTERLOG.COM>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Sunday, December 07, 2003 4:10 PM
Subject: Re: [EE:] Crystal Drifting


> At 10:40 AM 12/7/2003 -0300, you wrote:
> >Hello, friends.
> >
> >I rated this question as EE, because my problem happens with an Atmel 89C
> >series microcontroller, not a PIC.
> >
> >I use a 12 Mhz crystal, with two 33pF caps to ground, as requested by the
> >data sheets. However, I noticed the freq is not steady. It varies from
11.93
> >to 12.10 MHz, all the time. I would expect, in a 20 ppm part, much less
> >drifting than this, right ?
> >
> >Well, the PC board is ok, crystal and caps are very close to the micro's
> >oscilator pins, no external interference, etc. I have already replaced
the
> >crystal and the caps, and the problem is still there. What is happening ?
>
> Are you using HC49U or HC49US crystals, or those cylinder type?
>
> Best regards,
>
> Spehro Pefhany --"it's the network..."            "The Journey is the
reward"
> speff@interlog.com             Info for manufacturers:
http://www.trexon.com
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http://www.speff.com
>
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