Electrostatic discharge (ESD) clamp using output driver

US7362554B2 · kind B2 · utility

Assignee

• Silicon Labs CP, Inc. · US

Inventors

• James D. Austin · Austin, US
• Kenneth W. Fernald · Austin, US

Key dates

• Filing date: May 8, 2003
• Grant date: Apr 22, 2008
• Expiry date: Sep 20, 2024

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D89/819

Abstract

Electrostatic discharge (ESD) clamp using output driver. An electrostatic discharge (ESD) protection device for an output driver having a p-channel transistor and n-transistor pair connected between a power supply terminal and ground for driving an input/output pad therefrom. An ESD event detector is provided for detecting an ESD event on the pad. A drive circuit drives the n-channel and p-channel drive transistors in response to receiving a logic control signal to either drive the pad from the supply terminal or to sink the pad to ground. ESD protection logic circuitry is provided to cause both the p-channel and n-channel transistors to turn on when the ESD event detector detects an ESD event, the ESD protection circuitry disposed forward of the drive circuit such that the ESD protection logic circuitry operates independent of the state of the drive circuit.