Cmos latchup theory

Abstract The purpose of this paper is to study the CMOS latchup phenomenon from a non‐linear circuit theoretic standpoint by using some recently developed results on negative‐resistance devices. We introduce a simple mechanism to describe the latchup phenomenon based on a special circuit topology called feedback structure , which is shown to be responsible for the occurrence of latchup. Several guidelines are proposed to prevent latchup by destroying the feedback structure. In addition to the characterization of the steady‐state behaviour, we use a first‐order circuit model to analyze the latchup dynamics during the turn‐on process and give a stability analysis of the circuit dynamics. All existing techniques to prevent latchup are shown to follow naturally from our guidelines , which are derived using nonlinear circuit theory.