TPS51220A: TPS51220A low-side MOSFET damage issue

Hi Tommy, 

The schematic looks well. I have just one concern. FB divider resister is too small. it's suggested to use 43k ohm and 10.5kohm. But I'm not sure it's the root cause. 

1. please send me the layout to review. 
2. How does it damage? what conditions will it damage when you test? Did you plot waveform? please send me. 
3. Please plot SW, Vout and Vin waveform when it can normal work. it's better to zoom in SW waveform, I want to see SW rising time, falling time, overshoot and under shoot. 

BRs, 

Edwin. 

Hi Edwin,

thanks for your reply, please refer to the attachment file for the layout board file/ MOS 8D report/ switch node phase waveform.

if have any idea please let me know, because next week is chinese new year,so if need me to provide other information will be late,sorry.RSC-IMX61_E1907RSC603RO_A1_20150729-1000.rar496359_FDMS0312AS_Final+Report.pdfPhase pin waveform for Ti measured 20190201.docx

Hi Edwin,

sir, have any ideas for us?

Hi Yuchang Zhang,

the attachment file is a high/low side cross and switch node spike waveform for your reference, i think the customer can't catch the waveform during at damage,

because it happen on the end customer.