[sdiy] 2164 Expo correction

[Mike Pepper]

> > No.  More quiescent current also means more base current.
> > For an expo converter you would want a very low Rbe, but the
> > effective Rbe in the
> > SSM2164 is whatever the transistor delivers plus 450 Ohms.
> > You can't work around that since you can't get at the bases directly.
>
> Yes, that 450R resistor is the troublemaker.  Life would be much better if
> that weren't there!
>
Speaking as a person whose circuit design skills are not so much rusty as
thoroughly oxidised, I have a minor, and probably erroneous suggestion.

Might it be possible to feed the pin from a negative impedence
buffer/amplifier, tuned to cancel out the effect of the 450 Ohms?

||\/||ike