Patent ID: 9679891
Date: 2017-06-13
CPC Classifications: H01L,H02H

Claim:
1. An apparatus comprising: a first sensor circuit; a second sensor circuit, wherein each of the first and second sensor circuits are configured to detect an electro-static discharge (ESD) event; and first and second clamp transistors configured to be activated by the first and second sensor circuits, respectively, responsive to detection of the ESD event; wherein a resistive-capacitive (RC) time constant of the first sensor circuit is greater than an RC time constant of the second sensor circuit; wherein at least one of the first and second clamp transistors is coupled to well-biasing circuitry, wherein the well-biasing circuitry includes a pull-up transistor and a pull-down transistor coupled together and further coupled to a well of the clamp transistor, wherein the well-biasing circuitry is configured to bias a threshold voltage of the clamp transistor.