UCC21521: UCC21521

Sriya RG

Part Number: UCC21521

Hi!

We are trying to simulate and debug a circuit where UCC21521 is used to drive Hex bridge MOSFET(IXFH56N30X3) for motor load. In the simulation, we used IXT_96N15P MOSFET. We are facing convergence issues and the upper MOSFET that is connected to OUTA of the driver is not getting turned on. Individual MOSFET and Driver work fine.

Please let us know if connections that might have gone wrong or any other solution.

Thanks!

over 2 years ago

0 Krystian Plaskota over 2 years ago

TI__Expert 4065 points

Hi Sriya,

I am looking into this now and I will get back to you in a day or two.

Regards,

Krystian

0 Sriya RG over 2 years ago in reply to Krystian Plaskota

Prodigy 50 points

Thanks Krystian!

Also, Do you know how to connect NC terminals of UCC21521 in pspice for TINA?

0 Richard Herring over 2 years ago in reply to Sriya RG

TI__Mastermind 21675 points

Hello Sriya,

Krystian is out of the office at the moment, but should respond to your question within the next day.

Regards,

0 Sriya RG over 2 years ago in reply to Richard Herring

Prodigy 50 points

Hi Richard!

Thanks for the update!

0 Krystian Plaskota over 2 years ago

TI__Expert 4065 points

Hi Sriya,

There are a few things you can try:

In regard to connecting the floating pins in TINA, could you try either connecting them to ground or try connecting them to each other. I have had a circuit not simulate for me because NC pins were left floating so perhaps the same situation is in TINA.

Can you take a look here to see if this solves your issue? https://e2e.ti.com/support/tools/simulation-hardware-system-design-tools-group/sim-hw-system-design/f/simulation-hardware-system-design-tools-forum/409351/convergence-problem-check-the-analysis-parameters-in-tina#

Can you try removing all the inductors and external models and try running the sim to see if it still has convergence issues? If it runs, gradually add them back in 1 at a time to see which causes the problem.

Can you recreate this error in "Pspice for TI" to see if it will give you more details about the convergence issue? TINA's error message isn't very helpful in locating the source of the error.

Can you upload a picture of your schematic?

Regards,

Krystian

Power management

Power management forum

UCC21521: UCC21521