Electrostatic discharge protection circuit having high allowable power-up slew rate
AssigneeNVIDIA Corporation
InventorJau-Wen CHEN
Life of this patent
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Abstract
One embodiment sets forth a technique for providing electrostatic discharge (ESD) protection in complementary metal-oxide semiconductor (CMOS) technologies. A power supply RC-based ESD protection circuit having a 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.
Claims21
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 and pull-up sub-circuit 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 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.
A method for providing electrostatic discharge (ESD) protection for a circuit, the method comprising:
- receiving a transient voltage at an RC-based ESD protection circuit;
- determining that the transient voltage represents an ESD event and that ESD protection should be activated;
- pulling up a switch node by an RC filter and pull-up sub-circuit to enable an ESD sub-circuit to conduct an ESD current;
- deactivating the RC filter and pull-up sub-circuit once the switch node is pulled-up;
- and
- isolating the switch node from a VDD supply and a GND supply by a controlling sub-circuit that is activated as the switch node is pulled up, wherein the ESD sub-circuit continues to conduct the ESD current when the switch node is isolated.
An integrated circuit, comprising:
- A VDD power supply that is coupled to an input pin of the integrated circuit;
- and
- An RC-based electrostatic discharge (ESD) protection circuit that is coupled to the VDD power supply, wherein the ESD protection circuit comprises:
- an RC filter and pull-up sub-circuit that is configured to detect an ESD event and pull-up a switch node;
- a controlling sub-circuit that is coupled to the RC filter and pull-up sub-circuit and is activated after the switch node is pulled up by the RC filter and pull-up sub-circuit and configured to isolate the switch node from the VDD supply and a GND supply after the switch node is pulled up by the RC filter and pull-up sub-circuit;
- 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;
- and
- a controlled pull-down sub-circuit that is coupled to the switch node and controlled by the controlling sub-circuit to pull the switch node down and disable the ESD sub-circuit when the ESD event terminates.
Dependencies are inferred from the claim text.