On Mon, 02 May 2005 10:18:00 -0700, the renowned Jim Thompson
wrote:

On Mon, 02 May 2005 11:53:54 -0400, Albre wrote:

Thanks Jim,

It sounds too good to be true though, is it really that easy?

A

A cmos r/c oscillator might work just fine, but I can't figure out how
to vary the frequency with a dc input voltage::


Vary VDD



I know it works for ring oscillators used as VCO's, but as soon as you
add R/C's I'm not sure if it still works.

Frequency shouldn't change more than a few percent with Vdd over the
normal operating range of a CMOS gate.

You could make a VCO with an op-amp and a comparator, but how about
the VCO portion of a 4046?



Best regards,
Spehro Pefhany
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