how do i know how much current of an opamp can output?

[greenplanet]

how do i know how much current of an opamp can output by using Cadence Spectre?
what would the test circuit look like?
If i were to fab the opamp, how should I test it?

thanks.

 

[kwkam]

you can config the opamp as buffer and connect a 1ohm at output to half between vcc and vee. Then input a small sine wave and detect the current output. You can do similar in testing except use a larger resistor

 

[Johnson]

in Cadence Spectre, you opamp's final stage transistor size and feedback loop parameters will specify the output current capability!

 

[pixel]

Connect OPamp as a buffer for example and put between output and ground idc...
then simulate dc sweep for dc current of idc for example from -1m ...1m
If OPamp has enough current capacity output current should not affect on a voltage between positive and negative input node should be close. If not you will see that opamp does not work any more

 

[greenplanet]

thanks all..

but is it necessary to have the opamp output a current say about 1mA such that it can be characterized after fabrication?

If the opamp is to be characterized on wafer, what kind of test structures should be included?