Dear Linear now Analog,
in my design I have LTC4269-2 used essentially as shown in the reference design. In particular, there is an electrolytic capacitor at the power input:
I was measuring input voltage POE-POENEG (it was nearly 50V) while the converter was operational. VNEG was nicely pulled down to POENEG.
During that measurement I made a short from POE to POENEG and that resulted in damage of the chip. The input voltage could have been still applied, but VNEG was no longer pulled down to POENEG.
In my opinion the damage must have been caused by rapid discharge of C35. The current discharging the capacitor must have passed though LTC4269-2 and probably its intensity was too high. Is LTC4269-2 protected against events like this one? Is there any rating for the max. surge current? The only relevant rating I know is
VNEG Pull-Up Current ..................................................1A
Best regards,
Adam
