Diode and transistor equivalent circuits for transient operation

Solid-state devices have complex energy storage effects that complicate their transient operation. A frequently used method of analysis is that of charge control. This method relies upon quasi-static equilibrium and may have significant errors for high-speed operation. The method proposed uses a series approximation to a convolution integral solution. The first term of the series is equivalent to charge-control operation and higher order terms provide improved accuracy in terms of lumped elements of an equivalent circuit, but the real merit of the series form is its ready adaptability to computer- programmed node-branch circuits analysis.