Solid-State Electronics, Vol.44, No.1, 133-142, 2000
Current saturation control in silicon emitter switched thyristors
In this paper a novel Dual Channel Emitter Switched Thyristor (DC-EST) structure with diode diverter connected to the P-base region is shown to provide reduced saturation current density without compromising the on-state voltage drop. During the on-state, the diode diverter does not carry any current and the P-base region is effectively floating in potential, which results in a low on-state voltage drop. During current saturation, as the P-base potential rises, the diode diverter diverts the holes collected in the P-base, thus leading to an improved forward biased safe operating area (FBSOA) The saturation current density is lowered significantly which is desirable to achieve a good short circuit safe operating area (SCSOA). The dynamic clamping behavior of the diode diverter allows for independent optimization of the forward drop and saturation current density. Experimental results are reported to confirm the superior characteristics observed through simulations. The novel diode diverter DC-EST structure is found to be particularly suitable for high voltage (4 kV) applications.