Thermal impedance extraction for bipolar transistors

Abstract

This paper describes a method for extracting the thermal impedance of bipolar transistors. The measurement is a two-step process: first the fractional temperature coefficients are calibrated at dc and then a transient step response is measured to extract the thermal spreading impedance. Measurement configurations and an example measurement cycle are shown. The measurement results can be fitted to multiple-pole models for use in compact circuit modeling in SPICE.