Symbol Names: CSW
Syntax: Wxxx n1 n2 Vnam <model> [on,off]
Example:
W1 out 0 Vsense MySwitch
Vsense a b 0.
.model MySwitch CSW(Ron=.1 Roff=1Meg It=0 Ih=-.5)
The current through the named voltage source controls the switch's impedance. A model card is required to define the behavior of the current controlled switch.
Current Controlled Switch Model Parameters
| Name | Description | Units | Default |
| It | Threshold current | A | 0. |
| Ih | Hysteresis current | A | 0. |
| Ron | On resistance | Ω | 1. |
| Roff | Off resistance | Ω | 1/Gmin |
The switch has three distinct modes of current control, depending on the value of the hysteresis current, Ih. If Ih is zero, the switch is always completely on or off according to whether the control current is above threshold. If Ih is positive, the switch shows hysteresis with trip point currents at It - Ih and It + Ih. If Ih is negative, the switch will smoothly transition between the on and off impedances. The transition occurs between the control currents of It - Ih and It + Ih. The smooth transition follows a low order polynomial fit to the logarithm of the switch's conduction.