Compensated Exp generators and VCO's
don at till.com
Thu Jun 8 22:52:31 CEST 1995
Actually you don't need that opamp/fet precision current source
thingie at all. The negative input of the exponential converter opamp
is gonna be at ground, so all you need is a resistor to a reference
voltage. The voltage source at the high end of the VCO cap would
probably work fine.
I'm a firm believer in simplicity.
(And I'm really surprised how well this web page approach works --
it's the high-tech equivalent of scrawling on a napkin!)
And this circuit seems to be asking for a p-channel vfet to discharge
the VCO cap.
One other thing, and this is entirely personal user-interface
aesthetics, I'd recommend averaging the switched outputs instead of
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