Dear :
Custom 's products is wall switch , the Schematic same as ucc28740EVM-525,
But when load up to 5V 2A , The Surface of TVS D3 is too hot, the temperture up to 110°C.
When check the mosfet Vds waveform as follow and the leakage inductance of transfomer is 15uh
I suggest to increase the resistance of R12, and add a 10nf capacitor beteween TVS tube. but it doesn't work.
i want to know the temperture of TVS tube is normal or not? if not , how to reduce the temperture of TVS tube.
thanks a lot.