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Attributes depending on the value of voltages and currents (Read 3318 times)

Emmanuele

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Posts: 11
Geneva, Switzerland

Attributes depending on the value of voltages and currents
Oct 15^th, 2009, 5:02am

HI to everybody.
I'm using Design Entry HDL (in Cadence SPB 16.01), an upgraded version of PSpice.
I would like to know if it's possible to define the value of an attribute (say, the resistance of a resistor) depending on the istantaneous value of a voltage or a current in the circuit.
I know that it's possible to define values which depend on constants, or fixed parameters; but I'd like to define comething more complex.
For instance, I'd like to define a resistor with a resistance depending on a function of the integral of the power dissipated in its (ie R*I^2).
Any suggestions?
Thanks a lot,
Emmanuele

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Geoffrey_Coram

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Massachusetts, USA

Re: Attributes depending on the value of voltages and currents
Reply #1 - Oct 20^th, 2009, 5:17am

I'd write the model in Verilog-A.

If you're stuck in PSpice without Verilog-A, I expect you could write a subckt with dependent sources that measure the I and V of the resistor, make a current that's equal to I*V, and dump that onto a capacitor; the instantaneous voltage on the cap is then the integral of the dissipated power. (You'll need a resistor to ground for the dc solution, but you can make it very large if you're not modeling the heat transfer away from the device.)

If at first you do succeed, STOP, raise your standards, and stop wasting your time.

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