Switching Time of a Transistor with Tunnel Diode Coupling

The analysis of the switching action of a tunnel diode is extended to include the effects of the collector transition region capacitance which arise when a tunnel diode is driven from a common-emitter transistor stage. A piece-wise linear analysis is used which predicts the collector voltage waveform and switching times with good accuracy. The turn-off time constant is shown to be related to the transient current gain
\delta_0 = \frac {\alpha_0(C_L + C_{TC})} {(1-\alpha_0)C_L + C_{TC} }
rather than directly to the static current gains
\alpha_0
or
\alpha_0/( 1 - \alpha_0 )