The importance of the non-quasi-static bipolar transistor model for circuit applications

The need for non-quasi-static bipolar models is examined from a practical viewpoint in order to optimize compensation capacitor value, improve performance, and reduce chip area. This need depends on the circuit under study. The utility of non-quasi-static equivalent circuits in small-signal applications is investigated. The circuit example studied is a lateral p-n-p transistor used as a series pass transistor in a series voltage regulator. For the series voltage regulator, the non-quasi-static inductance model correctly predicts the rapid falloff of the magnitude of the current gain and thus reduces the required internal compensation and subsequent circuit area