LMV7239 Breaks TINA Simulation

Samuel Jaffe

Other Parts Discussed in Thread: OPA684, OPA2684, LMV7239, LMV7291, TINA-TI, LMV7271

Hi E2E,

My customer is simulating the OPA2684 and the OPA684 in TINA. The sim works fine until he imports the LMV7239 comparator. Once imported, TINA fails to find an operating point for the OPA2684. If the LMV7239 is replaced with the LMV2791, the sim works fine again.

The LMV7239 reference design runs fine by itself.

He imported the LMV7239 from SpiceRack. Is there anything special that needs to be done to get this working?

Thanks!

-Sam

over 7 years ago

0 Paul Grohe over 7 years ago

TI__Mastermind 49906 points

Hi Samuel,

I moved your post to the Simulation Forum, as the LMV7239 model is supported by the Webench team.

The LMV7291 (LMV7271) model is an older, simpler National PSPICE macromodel. The LMV7239 model is a newer TINA-TI model from the Webench group.

Looking at the LMV7239 model, the inputs are reversed from the op-amp standard, and the model comments note that there are some settings inside the model to optimize the propagation delay.

Make sure the inputs are correct, and you may need to edit the model to change the properties (right click on symbol, Enter Macro, edit then click the folder icon to save).

Are there any high impedance nodes >10MEG? Make sure the GMIN parameter is set to 1p or less (Analysis->Set Analysis Parameters). Also try setting "Zero Initial Values" for the Transient Analysis.

Regards,