Wood, Herron & Evans, LLP
RC-triggered semiconductor controlled rectifier for ESD protection of signal pads
RC-trigger circuits for a semiconductor controlled rectifier (SCR), methods of providing electrostatic discharge (ESD) protection, and design structures for a RC-trigger circuit. The RC-trigger circuit is coupled to an input/output (I/O) signal pad by an isolation diode and is coupled to a power supply voltage by a power supply diode. Under normal operating conditions, the isolation diode is reverse biased, isolating the RC-trigger circuit from the input/output (I/O) pad, and the power supply diode is forward biased so that the RC-trigger circuit is supplied with power. The isolation diode may become forward biased during ESD events while the chip is unpowered, causing the RC-trigger circuit to trigger an SCR configured protect the signal pad from ESD into a conductive state. The power supply diode may become reverse biased during the ESD event, which isolates the power supply rail from the ESD voltage pulse.
International Business Machines Corporation
H H Y H
H03K H01L Y10T H02H
inventional inventional additional inventional
Junjun Christopher S. Souvick Robert J. Tom C. Michel J.
Li Putnam Mitra Gauthier, Jr. Lee Abou-Khalil