I have experienced some startup-problem with the TPS54525.
My system consists of a webench-designed converter using TPS54525 with 6-10V input and 5V 4A output. The converter powers a ETX type computerboard consuming about 2A@ 5V. The 5 V is fed to the ETX-board via a PIC controlled Mosfet switch(IRF9130). At the first tests the switch was replaced with a jumper and this did not work. The converter could not handle the inrush current at power on and the converter died. Some startup attempts(less then one out of ten)was successful. I then increased the softstart capacitor and then it seemed to work OK.
Then I removed the jumper from the mosfet switch, and the problem was back. The converter powers up at power on but when I activate the switch to power the ETX-board, voltage drops and the converter gives up. I tried to solder a ludicrous amout of capacitors between the converter and the switch in order to handle the inrush current but the converter dies and must be restarted.
I have also tried to add a 100pF extra to the 22pF Cff but that didn't help.
According to datasheet all protective functions seems to be non-latching, but my problem is actually latching.
See attached schematics.
Any ideas how to solve this?
Best Regards
Lars Mikaelsson