Simulating the current mirror with a self-heating BJT model

摘要

A Gummel-Poon (GP) BJT (bipolar junction transistor) model that includes self-heating is presented, and a current-mirror circuit is used to show its significance. Self-heating thermal effects are modeled by a simple electrical analog circuit, which also provides BJT junction temperature as part of the CAD solution. Both discrete-BJT and IC mirror circuits are tested. The self-heating model correctly simulates the temperature stability of the IC mirror circuit where the BJTs are in close thermal proximity. For the discrete-BJT circuit, a standard GP model produces errors up to 84% versus 6.1% for the self-heating model.