Attached is a schematic for a simple one-pin ideal voltage limiter or clamp. When you apply this to a signal line, the voltage cannot rise above the "vlimit" value. (Note that the "Maximum Output Voltage" parameter on E0 must be set to zero volts for it to work.)
It works by turning on a current sink feedback loop when the voltage on the "clamp" line exceeds the "vlimit" value, thus limiting the voltage to "vlimit".
application would be where you are using ideal current sources to power up test
benches. Adding a clamp to each line will keep them from exceeding the supply
rail, especially in cases where you are running power-down
sims in which the current inputs are blocked by a switch.Originally posted in cdnusers.org by Hugh
It would be
possible to overdrive it with a strong enough drive level, so make sure it does
what you want it to before using.