Cadence Spectre - resistor dependent on equation

[harry456]

Is it possible to have a resistor in Cadence's Spectre (Spice) that is dependent on an equation like r = 2 * 1/(Vx - Vconst) with Vx as a net voltage?

 

[Dominik Przyborowski]

It is possible in ADE XL environment with 2 tests - 1st for calculating voltage at interest node, which is refered to second one.

 

[harry456]

Could you be a bit more specific, thanks?

 

[dick_freebird]

I think this is best done in veriloga (which Spectre digests
just fine, and Cadence supports editing and view-switching).
You will want to error-trap that denominator, and a poly-
source / analogLib primitives kludge probably doesn't have
much for that.

I'd recommend to find a resistor veriloga model, off the Web,
and just mess with the guts.

 

[erikl]

SPICE can cope with a behavioral resistor, s. this snippet:
View attachment HSPICE_User Guide_Simulation and_Analysis_Version_E-2010.12_December_2010_p174.pdf