Bipolar Device Model

The UCB bipolar transistor model is a hybrid of the Ebers-Moll [2] and Gummel-Poon [3] models. With a minimum parameter specification of IS, BF, and BR, the model defaults to the more simple Ebers-Moll model. The Ebers-Moll model is ideal because it neglects base width modulation, parasitic resistances, and high current injection effects.

Inclusion of additional parameters activates elements of the Gummel-Poon integral charge control model, which can provide greater accuracy. The Gummel-Poon model provides superior representation of the current flow in the transistor's base. It also provides accurate representation of parasitic resistances at all terminals, capacitance across all junctions, current-frequency effects, and temperature effects.