Hi,

I tried finding slew rate of a 2-stage opamp.. but for some reasons the output waveform gives oscillations. I thought I would have switched the input terminals.. but that looks good. Bias circuit is fine too. It gives the constant voltage of 0.4 V to bias NMOS. What else could be a possible reason for such behavior?

I will appreciate any help.

Regards,
Kanu

hi kanu,

method of finding slew rate for any class of an op with any method of compensation is same..because even if you don't have any compensation may be some parasitic cap will charge with ramp profile. Simulate and let me know i am sure you don't get into any problem.

Hi Tosei,

Thanks for your reply. I asked above question about uncompensated opamp, as I wanted to confirm if I measure transient response of opamp for pulse in open loop configuration.. will this be enough to determine its slew rate ? If so, then I don't need to worry. Otherwise first I will have to make my opamp stable for unity gain configuration

I think from your post, you do mean that transient response is enough. Do let me know if you think I have interpreted it wrong.

Thanks,
Kanu