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PMP21529: The HO is abnormal and the LO is normal

Skylar Li
Intellectual 940 points
Part Number: PMP21529
Other Parts Discussed in Thread: UCC27211A

Tool/software:

Hi Experts,

This is Skylar responsible for GREE. GREE refers to our reference design PMP21529. GREE shorten Q4 and removed Q3 first to test UCC27211A's function. MCU is set as 80% and 20%.

Here are the HO and LO waveforms as below.

 

After suffering the abnormal output of HO for a while, the UCC27211A is damaged which causes the 12V VDD is shorten.

Could you pls help on this issue? Thanks!

BR,

Skylar

  • 0
    TI__Intellectual 940 points

    Hi experts,

    Adding more information:

    1. The deadtime is 4%, PWM frequency is 75khz.

    2. When only connecting 12V VDD, the HO and LO could function normally and Vcboot also has stable 12V.

    But when both having 12V VDD and 48V Vdcbus, the HO and Vcboot could not function normally. The HO waveform is as below.

    Vcboot could not reach to 12V anymore. 

    Here is the layout as below.

     

    Pls feel free to give me advice. Thanks!

    BR,

    Skylar