I am using LTC1766-5 IC to convert the voltage from batteries, approximately 42 V, to 5 V in order to power a BMS. It consumes 0.25 A. The problem is that when I apply more than 40V to the DCDC it gets damaged.
I use a 47 uH inductor, a 100 uF output and ceramic capacitor, and a 0.72 forward voltage diode. At 200 kHz the inductor values decreases to 45 uH, the capacitor value decreases to 20.5 uF, the ESR is 2 mOhm and the ESL is 3 pH.
The circuit is:
I think that the error is related to the operation frequency but I don't know how to change it because the LTC1766-5 IC don't have the FB pin.
How can I apply to Vin more than 40 V without damaging the device?