[sdiy] Operational Transconductance Amplifiers

[David G. Dixon]

> > > "An OTA is basically a two quadrant multiplier. It multiplies an
> > > input voltage by a control current and produces a current as its
> > > output. The OTA's transfer function is that of a differential
> > > transistor pair, which is pretty convenient, although, a bit tough
> > > to analyze."

By the way, Walker, while you're busy learning about OTAs, you should have a
look at the datasheet for the SSM2164 quad exponential VCA as well.  Those
VCAs (or, more precisely, pairs of those VCAs) can do just about everything
the OTA can, but without the distortion.  They only have a single current
input, rather than the differential input of the OTA, but within that
limitation, there are very few things you can't do, often easier and better,
with a 2164 VCA or two.