This process takes only a short time for the current and the current gains to increase enough to satisfy Eq. (4.2). For anode-shorted devices, the mechanism is similar but the anode short impairs the turn-on process by providing a base-emitter short, thus reducing the p-n-p transistor gain, which is shown in Fig. 4.4. The composite p-n-p gain of the emitter-shorted structure is given as follows: