IC failure cause debugging

Hi,

Thanks for contacting Analog Devices!

I am transferring your query to focus FAE.

Regards,

Tech Support.

In LT spice simulation I had found that, Current is flowing from the IC (Vin) pin to capacitor C502 and the voltage at C502 increases up to Vin. It shouldn't be happened because I had put the series zener diode at Vin pin to reduce the voltage applied to Vin pin since the maximum operating is 600V. Can you suggest a solution to limit the voltage applied to Vin pin.

In Lt spice simulation I had found that the current flowing from Vin pin of the IC to Capacitor C309 and charging the capacitor to input voltage. But it shouldn't be since i had put the 56V zener diode in series voltage at Vin should be less than input voltage. I need to be operate at 540V dc input so to safely operate the IC  can you suggest any alternate solution to limit the voltage to Vin pin since maximum operating voltage is 600V