What's wrong with this opa?

[wjxcom]

Hi all: Please look at the OPA in the attachment, after I perform the TRAN analysis, I find the result is so strange!

From the AC analysis, the PHASE MARGIN is 60, and the BANDWIDTH is 40MHz, but from the TRAN analysis, I think this OPA is not stabilization! I do not know why???

Hi all, would you help me please? thanx!!!

 

[amriths04]

could you please upload your schematic alone in paint or something.

 

[gte582w]

Did you run open loop or close loop? Notice that
OPA has high open loop gain, so even if you apply
very small input, the output will swing rail-rail,
looks like oscillation.

 

[kivvzhou]

i can't see you file

 

[pmr9]

plz upload with right format ur file

 

[wjlzhx]

where is your load ???

when you simualte ac ,you must add your load,because when add different load your stabilization is different.

 

[analog_prodigy]

please load in paint

 

[liuyonggen_1]

do not believe the AC analysis completely!!
tran analysis belong to large sigal
AC belong to small signal

 

[pseudockb]

Dear wjxcom,

Could you please attach your ac and tran simulation result as well. We can't do anything without looking at the plot. Thanks!

 

[jjsnail]

do not believe the AC analysis completely!!
tran analysis belong to large sigal
AC belong to small signal