Bidirectional DIAC Devices with Two-Stage Triggering

A version of dual-direction SCR (DIAC), with control of the holding voltage and turn-on electrical characteristics by layout parameters, is presented. The effect of additional p-emitter region inside the device floating isolation region on the desired device characteristics is studied. By using an n-collector and/or a p-emitter in the blocking junction of the device, the holding voltage and high current capabilities of the device can be optimized to system level requirements. Experimental measurements and comprehensive mixed-mode TCAD simulations are presented for a 20V tolerant system level cell.