[sdiy] Tech question on saw VCO

[Neil Johnson]

> Tim Ressel wrote:
> > When connecting the output of the comparator to the gate of the FET,
> > sometimes I see a resistor with a speed-up cap across it. My
> > particular schematic has no such resistor/capacitor. Is it needed
> > and/or important? I assume its either current limiting or oscillation
> > supression.

Whereabouts _exactly_ is this resistor/capacitor?  There is a
resistor-capacitor from the comparator output back to its input to form
the reset monostable.

However, if it is series with the FET gate then its possibly to do with
reducing the drive to the gate to improve switching time.  See AofE 2ed
p.908.

Cheers,
Neil

--
Neil Johnson :: Computer Laboratory :: University of Cambridge ::
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