Modeling of temperature dependent IC-VBE characteristics of SiGe HBTs from 43–400K

This paper examines modeling of IC-VBEfrom 43 to 400 K in a 50 GHz peak ƒTSiGe HBT technology. Existing temperature scaling equations are shown to fail below 200 K. New temperature scaling equations are proposed, and demonstrated to work well over a wide temperature range of 43–400 K. Implications to VBE— T and ΔVBE— T for two transistors biased at different current densities are discussed.