LMP7704-SP: PSPICE Convergence issue with TI OP-AMP models only

Christopher Hirt

Part Number: LMP7704-SP
Other Parts Discussed in Thread: LMP2012, TINA-TI, LMP7704

Simple PSPICE signal conditioning circuit simulates as expected with multiple different Analog Devices OP-AMPS (eg AD8031) in a single supply configuration. Replacing the OP-AMP with LMP7704-SP, and simulation won't converge. Model indicates it was fixed for the single and asymmetric supply test. Circuit is single supply 3.3V. Tried LMP2201 from TI as well. Same convergence issue. Using Cadence PSPICE built-in OP-AMPs works. Need help on how to troubleshoot TI OP-AMP convergence issues.

over 1 year ago

0 Christopher Hirt over 1 year ago

Prodigy 10 points

Tried adding a negative symmetrical supply to the negative OP-AMP supply lead, and same issue still exists. Putting the Analog Devices part.back in simulates, but result is wrong as expected since it is a single supply design. But at least the simulation completes.

0 Christopher Hirt over 1 year ago in reply to Christopher Hirt

Prodigy 10 points

Tried LMp2012 too. Same issue, TI OP-AMP doesnt converge, others work just fine.

0 Raymond Zhang1 over 1 year ago

TI__Guru 51831 points

Hi Christopher,

Please send us your schematic, I will check it out in the morning. Here is an example, and it works fine.

LMP7704 02092023.TSC

Best,

Raymond

0 Michael Steffes over 1 year ago in reply to Raymond Zhang1

Guru 48195 points

Also Christopher, that model was updated in 2021 probably to a much more involved structure. TINA V11 had the original national model, transistor based, might run better,

LMP7701 original model.TSC

0 kai klaas69 over 1 year ago

Guru 140200 points

Hi Christopher,

this happens all the time when switching between simulators from different manufacturers.

Keep in mind that most of the TI's Spice models have been optmized for TINA-TI. So, one remedy is to simulate your circuit (or parts of them) in TINA-TI.

Kai

0 Raymond Zhang1 over 1 year ago in reply to Raymond Zhang1

TI__Guru 51831 points

Hi Christopher,

I checked LMP7704 PSpice model with other simulation tools and the simulation does not seem to have convergence issues. LMP2012 simulation works as well.

I am going to close this inquiry. Please let us know if you have additional questions.

Best,

Raymond

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LMP7704-SP: PSPICE Convergence issue with TI OP-AMP models only