Applications of the Charge-Control Theory

The consideration of the transistor as a charge-controlled device as proposed by Beaufoy and Sparkes has proved to be a useful way, both conceptually and analytically, to view the transistor. In this paper the charge-control theory is applied to a number of problems of interest to switching circuit designers. The charge-control theory is briefly reviewed to provide a foundation for the problems considered. The theory is then applied to describe in detail the ``on-demand current gain´´ ßs and its effect on circuit design. The basic equations developed for switching times are applied to an RCTL circuit and equations for rise, storage and fall times are developed. The effect of stray capacitance on switching times is developed in a particularly simple and unique way.