Multiple-finger turn-on uniformity in silicon-controlled rectifiers

Turn-on uniformity of two multi-finger silicon-controlled rectifiers (SCRs) with different combinations of anode/cathode regions are studied using the transmission line pulsing (TLP) tester. The finger turn-on mechanisms of these devices are explained from the current flow path and equivalent circuit views. The dV/dt effect of pulses with different rise times on the finger turn-on behavior of the SCRs are also investigated experimentally.