Thanks,eecs4ever said:You can used a voltage controlled resistor.
in the syntax below, phi1 is the control signal
and the switch connects 2 nodes, vin and vout.
the resistance between the 2 nodes is 100G ohms when phi1 is 0 volts.
When phi1 reaches 5 volts, the resistance is 1 mOhm = 0.001 ohm.
G1 vin vout VCR PWL(1) phi1 0 0,100G 5,1m
you can also refer here: