Other Parts Discussed in Thread: UCD3138
According to the UCD3138 full-bridge hard-switch development board, four full-bridge hard-switching power supply prototypes were made.
The input Vin: 20V~50V, no-load test.
When the input voltage is gradually increased from 20V, when the Vin reaches 40V-48V, 4 prototypes have 3 primary MOS tubes blown up.
2 fried ones were on the upper tube and one only fried one bridge arm.
It looks like a fried MOS tube caused by straight-through, because it is empty, the tube is 80V withstand voltage.
However, I observed the primary 4-way drive waveform and found no abnormalities.
Now I don't know how to start troubleshooting. When the voltage rises, I feel worried.
I hope that the expert guidance will find out why.