Hello everyone
We use ST1S14PHR to reduce from 40V input to 15V output. 15V are used to drive Mosfet (BLDC Motor Control). Lately we had a lot of problem with ST1S14PHR, because some parts failed during on field operation. We cannot understand what is the problem, because when parts came to us, we can only see ST1S14PHR is damaged, with pin 7 (Vin) burned, and we don't know what's happened.
40V Vin cames from a battery. We use a electolitic capacitor and a pair of ceramic capacitor in the input stage, as the image below can show.
We tested products on field for some months before say it was ok and before start production. After we start production we get negatives feedbacks, and discovered the problem on ST1S14.
Battery in the input should avoid high Vin transient, so we cannot understand why pin 7 burn.
Anyone has expenrienced something like that?
Any ideas?
Thank you
Best Regards
Roberto
