4046 VCO experiment

[Martin Czech]

The current source should be pretty linear but with some error at the
low end. (Why not use a jfet precision current source?).

I think the inner VCO circuitry is not published.  Linearity is not
neccessary for most of the applications.  Who will demodulate FM with that
chip anyway?  It seems to be fabricated in the very same CMOS process
then anything else of this logic family.  So there are limitations on
matching, mirrors etc. Certainly the internal integrator has low gain
(but high bandwidth).

Could you be more specific on the error?


m.c.