Negative-voltage-trigger SCR with a stack-gate ESD transient switch

摘要

A transient negative voltage pump circuit pumps the ESD voltage to a negative voltage. The negative voltage with the ESD voltage are used for early triggering of an SCR structure on the integrated circuit. In one version of the present invention, a pn junction diode of the SCR device is used as part of the negative voltage pump circuit. This saves the layout area while improving the ESD performance. The present invention improves the ESD performance of an SCR ESD protection circuit which is used for protecting the power bus or an IC pin during an ESD event.