i used the attached circuit with atmega 8 to drive dc buck converter and it was working very well , then i increased the input voltage on the drain to 20v and the input current was 4 A (from a power supply ) suddenly the output on Ho of IR2112 was zero when i removed the converter the output on Ho was 7.6 v dc constant when the volt on drain Vd was 9.6 . and when i connected power resistor to the source of the mosfet Ho was zero ,did i lost the driver ?
also I noticed that when I increased Vd to 20 volt the output on IR2112( Ho) increased too ,the pwm was amplified to 25 v on the Mosfet gate how could the IRfz48 mosfet survive while Vgs from (10-20 v )?