"Nutcase Kook"
Jon Elson wrote:

Would "suicide diode" be a valid term for searching within a supplier
site?. I've come across guaranteed VTS/diode failure to short and never
open, before , but not able to nail it down. Would you know of any
VTS/diode type number that is definitely made for this purpose?
No, that's my own description. Digi-Key part
SA5.0ALFCT-ND is a representative part, although not the one
I've seen in a particular power supply. (I can't find the
part number of that unit right now.)



I still cannot find specifically stated , designed to fail short circuit
in any associated datasheet for that TVS. Of course any device might fail
short or even frequently fail short but I've still never found any TVS
designed and stated as such to fail short for safety purposes, ie as you
succinctly term such a theoretical device , a suicide device


** Semis like zener diodes and power transistors fail short when over
voltaged or overheated and the melted silicon chip does not repair itself.
So, the only way it can go open is if a feed wire fuses after the event.

Zeners ( even 400mW ones) have the chip fitted between a pair of copper
slugs so there is no feed wire.

Notably, Hitachi lateral mosfets in TO3 pack have aluminium gate and drain
feed wires designed to fuse if the chip ever went short - creating the
unique situation where one Hitachi mosfet in a parallel group could become
short ( drain to source) and yet the power amp still functions.

One then picks out the dud by noting it is much cooler than the rest.



.... Phil