For PFC and AC to DC conversion, I am using UCC28019A, I built the circuit on the general purpose PCB as per the reference schematic provided in the datsheet.
except for some components like inductor Lbst is 560uH, capacitor Cout 560uF, which are marked in the picture attached below.
But here are the problems,
- First I have given Vcc alone and took readings of each pin, I am getting the voltages as per described in the datasheet, Since IC is working fine stand alone, I have given mains AC line and turned off Vcc, to see any discrepancies, but there were no irregularities found.
- So this time I have given Vcc first and connected AC mains to the input side.surprisingly transistor got tripped, each pin is giving short circuit to the other respective pins. since the transistor is tripped, there is a virtual short between line and neutral, so the fuses are getting blown away, each time I am providing AC to the circuit. I don’t know why this happened. Please explain me.
- Also, when I suspected transistor got tripped, to verify, i removed transistor from the circuit, left the area open and powered ON, but this time, upon turning OFF AC mains, IC also got burnt (Vcc is present while IC got burnt, getting from lab bench power supply).While IC is burning, The lab bench power supply went to constant current mode, indicating short circuit inside the IC, but after IC burnt, the power supply again went to Constant Voltage mode.
Please help me to understand the issue so that I would be able to make the circuit.