UCC28880: UCC2880 damage

Raymond He

Expert 1990 points

Part Number: UCC28880

dear

UCC2880 damage in mass product，attachment is about ucc28880 BUCK voltage and current wave analyze，any advise？thanks in advanceER046-UCC28880 test wave(1).xlsx

over 2 years ago

0 Yunsheng Qu over 2 years ago

TI__Genius 9790 points

Hi, Raymond

Could you tell us the input and output condition when UCC28880 was damaged? and which pin is abnormal after damage?

Yunsheng

0 Raymond He over 2 years ago

Expert 1990 points

The input voltage of our products is 90V-264V. The input voltage used by Japanese customers is 90V pin3，pin4

0 Jaden Ning over 2 years ago in reply to Raymond He

TI__Expert 7080 points

Hi Raymond,

I have reviewed your schematic , here are some review comments which maybe have some relationship the failure .

1. There is no Pre-load resistor on output , since the buck converter operates with a fixed minimum switching frequency at no load condition. without Pre-load resistor on output side. the output voltage will be charged to too high that up to damage the FB pin.

2. The part of D3 is FR107 which Trr is 500ns, too long Trr maybe cause high reverse current when the internal FET turn on . if the total reverse current exceed the safe operating area that maybe case failure of the device.

here is a application note which detail explained the principle and give a guide of how to chose D3 and D4.

https://www.ti.com/lit/an/slua855/slua855.pdf?ts=1623311616659&ref_url=https%253A%252F%252Fwww.google.com%252F

Thanks.

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UCC28880: UCC2880 damage