CAMALEAO
Full Member level 4
Hi all. Imagine you have a comparator with hysteresis and you want to determine how much trim you need.
You do MC sim.
Now if you simulate using DC simulation sweeping the input of the comparator, how would like to know the following:
We sweep up and determine the value by taking the input when the output reaches VDD/2.
The same when it is sweeping down.
By doing the difference of the two simulations we the sigma that we get from these two subtraction is the one that we have to check to define the trim range?
Or is something else that I need to do? For example, the offset of the comparator? If so, how to do this? I was thinking, select the voltage at which the comparator should trip and using the dc sweep again, the same one as above, going up subtract the reference by the middle point when sweeping up.
Now I have the offset voltage. Then what? Subtract this value from the hysteresis window?
I am a bit confused.
Thanks in advance.
You do MC sim.
Now if you simulate using DC simulation sweeping the input of the comparator, how would like to know the following:
We sweep up and determine the value by taking the input when the output reaches VDD/2.
The same when it is sweeping down.
By doing the difference of the two simulations we the sigma that we get from these two subtraction is the one that we have to check to define the trim range?
Or is something else that I need to do? For example, the offset of the comparator? If so, how to do this? I was thinking, select the voltage at which the comparator should trip and using the dc sweep again, the same one as above, going up subtract the reference by the middle point when sweeping up.
Now I have the offset voltage. Then what? Subtract this value from the hysteresis window?
I am a bit confused.
Thanks in advance.