VIPER012HS reset on 230VAC

[PLi P.1]

Hi, I used the VIPER012HS controller following the non-isolated flyback scheme proposed by the tool design suit (which is the same by the datasheet) but after making the pcb I get a reset problem with the 230VAC mains voltage. I tried to input a direct voltage of 200VDC to the diode bridge and the controller works. over 200VDC the controller resets continuously. I am attaching the reference schemes (the scheme proposed by the tool design suite and my scheme). I tried the same scheme as mine with ltspice with all the correct models and it works correctly. I checked if there are any problems or shorts on the PCB and everything is ok. I can't figure out where the error lies. did I forget to evaluate any important specifications? thanks, Paolo

[PSedl.4]

I have a similar problem with a viper16 buck topologie. My test board works fine with 150 VDC, but at 200 VDC continously resets every second. For the 50 ms the regulation is fine.

@PLi P.1​  Do you have found a soloution for your problem?

[PSedl.4]

OK, i think i got a solution.

when i attach small capacitors (1nF) to FB and LIM pins, the controler works fine up to 700 VDC.

i think my problem is, that i had a GND plane on the bottom and the routing of the floating switched nets was not short enough.

best regards