A transient analysis of latchup in bulk CMOS

Abstract

This paper presents an analytical model of transient latchup in bulk CMOS that predicts the time-dependent current and voltage characteristics of the parasitic p-n-p-n structure. Not only does the model describe the conditions for transient latchup, but it also predicts a previously unreported phenomenon of dynamic recovery, which we have verified experimentally. Compact Stability criteria are presented for the p-n-p-n structure that delineate the roles of ramp rate and circuit parameters.