Texas Instruments Corporation

Kueing D Chen

Roland H Pang

A method and structure for protecting an integrated circuit from electrostatic discharges are disclosed. A Schottky diode (22) is connected to an input bond pad (12) and to a MOSFET transistor (17) which is desired to be protected. The normally high breakdown voltage required to drive the Schottky diode (22) into conduction is reduced by providing a trigger transistor (24) for prematurely triggering the diode (22). When the base-collector junction of the common emitter configured trigger transistor (24) is driven into avalanche breakdown by the electrostatic discharge, charged carriers (60) are generated, and attracted by the Schottky diode (22). The base (54) of the trigger transistor (24) is biased during normal operations with a supply voltage, and during electrostatic discharges to a higher voltage by an inherent Zener diode (64). When normal power is applied to the integrated circuit (10), input latch-up immunity is enhanced, and when an electrostatic discharge appears at the input bond pad (12), the electrostatic discharge protection is enhanced.

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Plano, TX, United States of America

Kueing D Chen