UCC21521: TINA simulation Convergence problem with transient analysis

Gopalakrishnan Palanisamy

Part Number: UCC21521
Other Parts Discussed in Thread: UCC21551

Tool/software:

Hello ,

I have downloaded a PSPICE transient model of UCC21521 from the TI website and ran a transient simulation. However, the simulation fails to converge.

In transient analysis , it shows convergence problem if operating end point time goes beyond 50us for schematic 1 and 40us for schematic 2.

Kindly advise how to resolve the convergence problem and run transient simulation without error.

Thanks!!

0 Sean Cashin 1 month ago

Hi GP,

MOSFET models and diode models are notoriously hard to simulate in a swiching application. You should replace them with voltage controlled switches.

Here is a UCC21551 model, which is the updated device. Are you able to make any more progress with this model?

Best regards,

Sean

0 Gopalakrishnan Palanisamy 1 month ago in reply to Sean Cashin

Hi Sean,

Thanks. As you suggested, I will replace Mosfet models with Voltage controlled switches to check the transient response.

Besides, Both UCC21551 and UCC21521 models to be simulated in parallel to figure out difference in transient response.(Tr,Tf)

I will share the result on the same.

0 Sean Cashin 1 month ago in reply to Gopalakrishnan Palanisamy

The voltage controlled switches are much more simple for PSPICE to handle.

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