arbitray inpedance vs frequency spice model

What Spice program are you using? You can use tables in a voltage controlled current source in PSpice and LTspice (PSpice syntax can be used in LTspice). Table will have frequency and complex admittance.

Here's an educational listing on how to make a resistor from a VCCS where the resistance is controlled by a voltage.

VOLTAGE CONTROLLED RESISTOR EXAMPLE

*TO CHECK RESISTANCE, USE EXPRESSION V(2,0)/I(R1)

Vin 1 0 AC 1.0V R1 1 2 1N ;CURRENT MONITOR

X1 2 0 4 0 VCR

*CONTROL VOLTAGE Vadj 4 0 900V Rjunk 4 0 1

*VOLTAGE CONTROLLED RESISTOR SUBCIRCUIT

• 1.0 VOLT = 1.0 OHM

• +------- resistor terminal +

• | +----- resistor terminal -

• | | +--- pos control node

• | | | +- neg control node .SUBCKT VCR 1 2 3 4 G1 1 2 VALUE={V(1,2)/V(3,4)} .ENDS VCR

.AC DEC 10 1kHz 10kHz .PROBE .END

==================== A VCCS table with a frequency dependent admittance will look something like this.

.SUBCKT XDCR 1 2 G_G1 2 1 FREQ {V(2,1)}= R_I (

• 1000 12.41u 273.5u

• 1150 18.61u 319.4u

• 1300 28.13u 363.7u

• 1450 40.99u 407.5u

• 1600 60.94u 454.5u

• 1750 88.09u 493.1u

• 1900 121.5u 523.9u

• 2050 156.6u 542.4u

• ) .ENDS XDCR

As an excercise to the student, use your Spice skills to put together the above examples.

--
Mark

Also take a look at VVC.zip on the Models page of my website. ...Jim Thompson

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| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
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I love to cook with wine.     Sometimes I even put it in the food.

You might try playing with a combination of arbitrary behavioral sources (B), or dependent current and voltage sources (E, F, G, and H)

You can even use polynomials.

RTFM ;-)

--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
                                             (Stephen Leacock)

If you want answers to these questions I suggest going to

and search for the LTSpice group. This is a busy group, someone will know the answer.

Mark.