how to simulate open loop gain with hspice

[keith1200rs]

Yes, I have to say I like the scheme suggested by LvW better than the large RC method - more robust.

Keith

 

[dbmd]

either the large RC method or ideal buffer method forces the the dc value of the input and output to be the same. is there a different way to set the dc op of the input and output independently ?

 

[LvW]

either the large RC method or ideal buffer method forces the the dc value of the input and output to be the same. is there a different way to set the dc op of the input and output independently ?

Yes, of course. That's the method of offset correction.
Place a (small) dc voltage source at one of the opamp inputs and watch the output during dc analysis until it has reached the desired value. Thus, you can determine the offset voltage which has to be applied to keep the opamp in its linear region.

 

[dbmd]

either the large RC method or ideal buffer method forces the the dc value of the input and output to be the same. is there a different way to set the dc op of the input and output independently ?

Yes, of course. That's the method of offset correction.
Place a (small) dc voltage source at one of the opamp inputs and watch the output during dc analysis until it has reached the desired value. Thus, you can determine the offset voltage which has to be applied to keep the opamp in its linear region.

Thanks LvW. I sent you a PM.