I am using LTC4267 IC as a over voltage protection device. I have set the over voltage to 36v and the device is working fine. I have given a load of 1A. I have given 28v supply and 100V supply using diodes ORing circuit such that
1. If 28V is ON and 100V is OFF, then device input is 28V. The device works fine.
2. If 28V is ON and 100V is ON, then device input is 100V.
In second case when the 28V is ON for some duration, the device works fine and suddenly if 100V is switched ON, then the device gets damaged.
This happens only when 1A load is applied. Without load it works fine for this case also.
I have almost 10 devices like this.
Please help me to solve this problem.
Thank you for sending the schematic. Where is the 100V being generated from? Is it coming from CAP+?
Are the MOSFETs still functional?
It is possible that you are momentarily exceeding the absmax rating of the LTC4367, inductive spikes in your system could exceed the 100V absmax and damage the device. What is the rating of D3? if the maxmimum clamping voltage of this device is greater than 100V then it should be reduced.
If the problem persists please send this device in for FA so that we can see which pin failed.