My customer is using UCC28250 to design a half-bridge synchronous 150W power. lsolated transformer and driver IC TPS2812 are used for driving secondary synchronous Mosfet IRFB4310. An input OVP function is required and the protection threshold is 141V and recovery threshold is 137.5V. However, when decrease the input voltage from 141V to 137.5V , UCC28250 would enter a hiccup mode and one of the two synchronous driving PIN(SRA/SRB) was damaged(shorted to ground). Then the customer lower the recovery threshold from 137.5V to 121V, the hiccup mode was disappeared, but sometime the damage of SRA or SRB also happened. The customer wants a threshold of 141V and 137.5V, so I wonder is there any way to protect the SRA and SRB from damage? A capacitor bypass from input of the UC2812 is already used to make a dead-time delay, but the problem still exists.