Part Number:UCC28740
Hello,
I'm currently debugging a prototype of the UCC28740 + UCC24636.
5V - 2,5A
After one obvious correction around transformer primary (wrong polarisation) I get an unstable 5V on output. And the circuit cannot bear any load.
It seems that the UCC28740 was working properly on few switch, achieved to get a 5V but suffers a default and switch OFF.
We can see VDD drop below UVLO 7V
I was starting to investigate further with 2 differential probes but I burn a 2nd PCB (Rcs resistors). (on First PCB Rls, Rcs and UCC28740 burnt)
I got a differential probe between primary GND and VDD and the second one between primary GND and DRV.
Could the probe on the DRV triggers the Mosfet and build a short circuit on Rcs resistors?
Could you make a sanity check of my schematic before I go further on my live testing attempts?
Thank you
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Best regards,
Frans