OPA593: Simulation Models for Adjustable Current Limit Opamps

Hi Edward, 

Edward Keehr said:

It is possible to manually edit these SPICE files in order to obtain a particular current limit? If so, how would this be done, in particular for the OPA593?

The OPA593's ILIMIT behavior is not modeled either. But you may simply monitor the output current using a behavior model or a comparator, and trigger the overcurrent event when the output current exceeds a setpoint. 

If you tell me what you are doing, I may be able to provide additional suggestion. 

Best,

Raymond

Hi Raymond,

I'm trying to model the behavior of the amplifier as it encounters a progressively smaller resistive load to the point where it enters its current-limiting mode.

In line 54 of the opax593.lib file, the file claims to model short-circuit output current.

In simulation, this short-circuit output current does seem to be modeled and is about 300mA.

Changing the values of the voltage sources on lines 240 and 241 on the opax593.lib file from 300 to some lower value appears to alter the short-circuit current limit accordingly in simulation.

It would be interesting to know if such edits are correct and complete if my intention is to change the short circuit output current limit of the amplifier in simulation.

Thanks!

Hi Edward, 

Yes, the Isc is modeled, but I_limit is not. I did speak to our modeling engineer and he confirmed that the I_limit's behaviors are not modeled.  

In actual OPA593 power amplifier, the I_limit is near ~25mA or lowe I_limit range has larger %errors.

If you have other questions, please let me know. 

Best,

Raymond