A power bipolar junction transistor model describing static and dynamic behavior

The power bipolar junction transistor (PBJT) is investigated and modeled. Particular interest is concentrated on the injection charge in the collector layer that dominates the large-signal characteristics of the device. Based on the semiconductor physics, ordinary differential equations describing the injection charge are derived. These equations take into account the recombination, charging, and discharging processes in the collector layer. A network model for the PBJT is derived by adding these equations to a standard model. This model is implemented in the IG-SPICE language. The static behavior, such as the quasi-saturation, and the dynamic behavior, including turn-off under the strong drive condition, can be simulated and analyzed. The simulation correlates well with the measurement.<
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