ltspice
I would like to create a variable resistor as following:
R2=1 if i(R2)<1
R2=2 if 1<i(R2)<10
R2=3 if i(R2)>10
I know that the syntax is:
R=if(condition,valueiftrue,valueiffalse)
What if I have three intervals?
The .asc file and the IF statement law is also shown below.
What is the correct syntax to do that?
Monte Carlo analysis and worst-case is usually the way this is done, exactly as the linked article describes. For Monte-Carlo you don't have to change your components by hand, just run the Monte Carlo sims and the simulator will automatically change the components based on your Tolerance field. You have to run enough cases to get a statistically significant result, and you can calculate how many runs you need for a given confidence. Worst-case requires a little more work and knowledge of how the circuit works, but the linked article explains that as well.
This works for me.
I had to change the prefix to BV for [B]V4. And also use net names; it doesn't seem to take the voltage sources' names in those behavioral expressions.
What I need is something that activates a given pulse, or a behavioral voltage source that can create a pulse if a certain condition is true.
What you seem to actually want however is a PWL triggered ramp like so:
Also what you're describing is not actually called PWM. If you somehow need to modulate the width instead of triggering then see this solution.
Well assuming you only want non-zero rise (as in your graph) but zero fall time, and you want that combined with PWM, then you basically have to combine the above two solutions:
Best Answer
Then you can either
Create a B source with the conditional statements and an additional signal (which is useful for debugging)
Nest the
ifstatementsif(condition,valueiftrue,if(condition,valueiftrue,valueiffalse))