Enhanced PMOS-triggered PMLSCR with robust EOS immunity

An enhanced PMOS-triggered PMLSCR is proposed. Under the condition that both PNP and NPN BJT's are triggered simultaneously, voltage overshoot and turn-on uniformity can be further improved. From TCAD simulation, it is clear that with the help of trigger current, conduction path of SCR goes deeper and snapback voltage is reduced. By the designed power sequence, holding voltage and current of SCR devices considering self-heating effect are attained. Robust EOS immunity can be assured accordingly.