Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!decwrl!shelby!portia!dsl From: dsl@portia.Stanford.EDU (Dave Lauben) Newsgroups: sci.electronics Subject: Zener overvoltage protection Message-ID: <3780@portia.Stanford.EDU> Date: 19 Jul 89 23:49:53 GMT Sender: Dave Lauben Organization: Stanford University Lines: 33 Hello netlanders! I need to protect a differential discrete logic receiver (54LS32) against fault overvoltage of +/- 32 volts (continuous). I am not a circuit designer by trade, but this task has fallen to me. My plan is to use two zeners, but I can't decide which of two configurations would be more appropriate. Can anybody point out the relative merits of the two configurations? My concern is not only how well each would work but also reliability and failure mode effects... ____ ____ --/\/\/\/--o--------|+ | --/\/\/\/--o----o---|+ | | | | | | | | ,---' | 5 | | | | 5 | / \ | 4 | | | | 4 | --- | L | ,---' --- | L | | | S | / \ \ / | S | --- | 3 | --- ,---' | 3 | \ / | 2 | | | | 2 | ,---' | | | | | | | | | | | | | --/\/\/\/--o--------|- | --/\/\/\/--o----o---|- | ---- ---- Config. 1 Config. 2 If Config. 1 is preferrable, are back-to-back Zeners in a single package the best way to implement it? How 'bout TRANSORBs -- can they handle continous overvoltage? Thanks in advance for replys... -Dave lauben@star.stanford.edu