[sdiy] Need a SPICE model for SSM2164?

[David G. Dixon]

Here's a tip for all you simulators out there:

As part of my foray into SSM2164-based VCAs, I wanted to do some Multisim
simulations.  However, it turns out that there is no SPICE model for the
2164; at least, none that I can find on the web.  I tried simulating the
"simplified" schematic in Figure 23 of the datasheet, but this was a
disaster.

Then I found the solution (at least in Multisim): simply use a user-defined
component known as a "dependent nonlinear source".  This bad boy has
non-inverted and inverted outputs which can be defined as either voltage or
current, and its transfer function can be defined with a nonlinear
mathematical formula which depends on as many as 4 different input voltages
and 2 different input currents.  Hence, in order to simulate the 2164, all I
had to do was invoke the following formula:

I = I(V5)*10^(-1.5*V(1))

Note that I(V5) is one of the two possible input currents, and corresponds
to the input signal.  V(1) is one of four possible input voltages, and
corresponds to the control voltage.  This very simple function describes the
current gain of the 2164.  I've tested it within a simulation of the test
circuit given in Figure 1 of the datasheet, and it works like a charm.  I'd
be happy to send the simulation file to any Multisim users who are
interested.  Please let me know offline.