UCC28070A PFC Controller Shutdown

Alex Ori

Other Parts Discussed in Thread: UCC28070A, UCC28070

I am using the UCC28070A PFC controller for a 5kW Single Phase controller. I get a repetitive shut down from the current loop and cannot find the reason. Everything seems within specification of the Chip. If anyone can help please ?

over 8 years ago

0 Benjamin Lough over 8 years ago

TI__Mastermind 27135 points

Hi Alex,

Are you running into the peak current limit? How hot is the chip getting? Is it possible the chip is going into thermal shutdown?

Best Regards,
Ben Lough

0 Alex Ori over 8 years ago in reply to Benjamin Lough

Prodigy 45 points

No there is no chance of thermal shutdown. current limit maybe but I tried it with not much load. Suspect the synthesizer.

0 Alex Ori over 8 years ago in reply to Alex Ori

Prodigy 45 points

I can send some waveforms if you want, but cannot post it publicly

0 Benjamin Lough over 8 years ago in reply to Alex Ori

TI__Mastermind 27135 points

Hi Alex,

I sent you a friend request. You can message me the waveforms directly.

Best Regards,
Ben LOugh

0 CWilson over 8 years ago in reply to Alex Ori

Expert 1920 points

Do you have any RC-filtering on your current sense pin?

0 CWilson over 8 years ago

Expert 1920 points

If you read the datasheet, there is 2 different capacitors in the loop. One of them has to be larger (uF) than the other.

I have used the UCC28070 for a 1700W single phase PFC with great success. Just use the appnote/datasheet for your calculations.

Does it happen at all input voltages or only at low input voltage? Maybe your core saturates?

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UCC28070A PFC Controller Shutdown