UCC28070: UCC28070 GATE waveform issue

Jack Deng

Part Number: UCC28070

Hello Tis

I use the UCC28070 in my 4000W AC/DC project, the input is 185Vac-264Vac, PFC output is 410V

but there are some waveform issues when the PFC output power is greater than 3000W, and causing the PFC MOS damage soon.

could you give me some advive, thx.

UCC28070 PFC design.rar

over 6 years ago

0 John Griffin1 over 6 years ago

TI__Mastermind 34465 points

Hello Jack,
On your schematic you show totem pole drivers Q13,Q12 and Q33,Q34.
The collectors of Q13 and Q33 need to be connected to a low level DC bias voltage but instead they are floating.
This may be the issue you are facing at the 3000W power level.
Please check this connection.
Regards
John

0 Jack Deng over 6 years ago in reply to John Griffin1

Expert 1090 points

Hi John:
thanks for you support, I avoided this PCB problem during debugging, I connected the UCC28070 Gate and MOS Gate directly, but the issue still exists, thx.

0 John Griffin1 over 6 years ago in reply to Jack Deng

TI__Mastermind 34465 points

Hi Jack,
I dont know what you mean.
What pcb problem and what did you connect ?
If the MOSFET is failing you should try to get some scope wave forms for the gate drive (VGS) , the drain- source (VDS) and the drain current (IDS).
The MOSFET will only fail if its data sheet parameters are being exceeded so it is best to check this.
Do you think you can get any of these waveforms ?

Regards
John

0 John Griffin1 over 6 years ago in reply to John Griffin1

TI__Mastermind 34465 points

Hi Jack,
I am going to close out this post since I have not heard any new information in almost 2 weeks.
Please open a new post if you require further information.
Regards
John

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UCC28070: UCC28070 GATE waveform issue