UCC28780: About AC analysis using SIMPLIS

Tak

Part Number: UCC28780
Other Parts Discussed in Thread: UC3845

You are providing a simulation file of UCC28780.

The file can be transiently analyzed.
Is it possible to perform AC analysis?
I would like to consider the optimum loop compensation.

Or is it possible to analyze by replacing it with another flyback IC?
(For example, replace UCC28780 with UC3845 and perform AC analysis)

B.R. Tak

over 4 years ago

0 Jaden Ning over 4 years ago

TI__Expert 7080 points

Hi Tak,

In order to perform AC analysis, you have to add a AC SOURCE , a Bode Plot Probe and a POP trigger.

Firstly run Transient , then run AC + POP .

I don't think you can use UC3845 to replace UCC28780 since them are different control modes .

Thanks.

0 Tak over 4 years ago in reply to Jaden Ning

Intellectual 480 points

Dear Jaden

I tried with the file (UCC28780_TRAN_Si) you provided, but unfortunately I got an error.

Is it possible to tell me the specific settings?
I prepared and ran all of the AC source, board plot probe and pop trigger to simulate, but it doesn't work.

D.R. Tak

0 Tak over 4 years ago in reply to Tak

Intellectual 480 points

The error message is as follows.

<<<<<<<< Error Message ID: 5039 >>>>>>>>

The periodic operating point (POP) analysis
has failed to converge.  AC analysis will
not be performed.

0 Jaden Ning over 4 years ago in reply to Tak

TI__Expert 7080 points

Hi Tak,

I am not a SIMPLIS expert, Could you please try to get some help from other elsewhere.

Thanks.

0 Tak over 4 years ago in reply to Jaden Ning

Intellectual 480 points

Dear Jaden

Thank you for your reply.
I understood your situation.
I will contact SIMPLIS Corp.
(I am a license holder)

If possible, could you introduce a TI engineer who is familiar with SIMPLIS?

B.R. Tak

0 Jaden Ning over 4 years ago in reply to Tak

TI__Expert 7080 points

Hi Tak,

Simulation is just one of the method to optimum the loop compensation. another direct method is build a prototype and test it.

I can share some comments& proposals to you how to adjust the compensation once you can provide some bode plot .

Thanks.

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UCC28780: About AC analysis using SIMPLIS