My configuration:
LM22677 in standard application circuit(see attachment)
Components according to Webbench designer
Input voltage 24-32 Volts
Output voltage 18V
Output current 1.5-2A
The enable pin is driven from a 5 Volts logic signal
I switch the circuit on and off by the enable pin and measure voltages and currents. The temperature sensor is placed on the copper ground plane directly beside the chip. Generally the circuit works as expected.
At a temperature of 75 deg. C and an input voltage of 32 Volts the chip suddenly blows up in the moment when I put the enable pin on high. None of the values that I measure show any deviation before. No instability, no overshoot at the Switch pin.
What do I wrong? Any idea?
Thank you.