01-01-2016, 07:26 AM
Yes Jeffrey. Can't remember what that one is called, but I was talking about some similar failures in HV bipolar transistors to a guy from TI in Dallas, (on a discussion forum). Who called it punch through. A similar kind of thing commonly happens to power MOSFETs (but much more easily, static builds up on the gate region capacitance), US term is gate rupture and is an out of circuit handling problem, and not found very often in devices that are in circuit. Had a problem once with a switching DC-DC converter I was designing, for a high power off grid fluorescent lighting system. It ended up with a circuit suggested in some TI. application notes I found that used BUX xx bipolar transistors in the inverters. I bet the 320volt dc output surprised a few careless electricians. Easy money! The royalties have stopped now, f*****g LED's! Back to topic, is the failure mode that you are referring, the one where the transistors BE junction ends up open and the C to E ends up short? Regards. Andy.
