TPS40428: TPS40428 start up cause OVF and may shut down randomly

Hi Ti team,

I have build a board with TPS40428 and 2x CSD95378B for evaluation, using 12V input to provide 1V output, design reference from PMP9444

but now my system have 2 issues

1/ OVF are easily triggered when enable TPS40428

/resized-image/__size/640x480/__key/communityserver-discussions-components-files/196/Random-Shutdown.png

/resized-image/__size/640x480/__key/communityserver-discussions-components-files/196/Power-On-OVF_2D00_1.png

2/ Sometimes TPS40428 can operate normal, but it usually shut down within 5min

/resized-image/__size/640x480/__key/communityserver-discussions-components-files/196/Power-On-OVF_2D00_2.png

I have probed Vout and FB found they usually give a lot of ripples before OVF shutdown

Should I change the R/C value in the loop compensation circuit?

Thanks a lot.

Alex

/cfs-file/__key/communityserver-discussions-components-files/196/TPS40428-loop-calculation_5F00_20221018.xls

/cfs-file/__key/communityserver-discussions-components-files/196/TPS40428_5F00_output_5F00_OVF.pdf