Electrostatic discharge protection circuit having high allowable power-up slew rate

摘要

A technique for providing electrostatic discharge (ESD) protection in complementary metal-oxide semiconductor (CMOS) technologies is disclosed. A power supply RC-based ESD protection circuit having an RC value in the nanosecond range increases the allowable power-up slew rate so that fast power-up events (e.g., hot-plug and power switching operations) are not erroneously interpreted as ESD events. Because the RC value is small, the layout area needed for the RC-based ESD protection circuit is also reduced.

主权项

1. An RC-based electrostatic discharge (ESD) protection circuit, comprising:
a RC filter and pull-up sub-circuit that is configured to detect an ESD event and pull-up a switch node, wherein the RC filter is directly coupled to the pull-up sub-circuit and includes a resistor and a first capacitor having an RC time constant; a controlling sub-circuit that is coupled to the RC filter and pull-up sub-circuit and activated after the switch node is pulled up by the RC filter and pull-up sub-circuit and includes a source follower that is configured to isolate the switch node from a VDD supply and a GND supply after the switch node is pulled up by the RC filter and pull-up sub-circuit; and an ESD sub-circuit that is coupled to the switch node and is activated to conduct an ESD current when the switch node is pulled-up by the RC filter and pull-up sub-circuit.