[sdiy] Temperature Compensated VCO attempt - help?

[Magnus Danielson]

From: patchell <patchell at silcom.com>
Subject: Re: [sdiy] Temperature Compensated VCO attempt - help?
Date: Sat, 01 Feb 2003 11:42:33 -0800

Jim,

> I got enough data now that I could make a calculation, although, before I
> will make any claims, I still need more data, but, right now, I came up with
> 45ppM/C for the scale drift.  Now, if past experience is any indicator, this
> number will jump around a bit as I collect more data, however, this is an
> oder of magnitude better (old reading for this same VCO was 400ppM/C) than
> any data I have ever collected for a VCO.  I guess if this ends up working
> out OK, I'll have to send you some boards Scott.

In the neighborhood of 45 ppm/C is much much better than the uncompensated case
of 3300 ppm/C. When you are looking at that kind of temperature sensitivites I
think the milage can vary depending on what other components are in the VCO.

Jörgen reporten on what seemed to be temperature dependence on the LM311
comparator in one of his designs. Both resistors and caps can also change
depending on which quality was chosen.

Anyway, it seems mighty encouraging. The question I'd like to ask, at least
retorically, is which stability is needed?

Cheers,
Magnus