US 6,724,603 B2 · Electrostatic discharge protection circuitry and method of operation

Abstract

An Electrostatic Discharge (ESD) protection circuit (9) includes a plurality of I/O and power supply pad cells (22, 40) that comprise external pads (31, 41) and circuitry requiring ESD protection. The protection circuit includes an array of shunting devices (36, 46) coupled in parallel between an ESD bus (14) and a VSS bus (18) and distributed among the plurality of pad cells. One or more trigger circuits (50) control the shunting devices. ESD events are coupled from any stressed pad onto two separate buses: the ESD bus which routes the high ESD currents to the positive current electrodes of the multiple shunting devices, and a Boost bus (12) which controls the trigger circuits. During an ESD event, the trigger circuits drive the control electrodes of the shunting devices to a voltage level greater than possible with prior art circuits, thereby reducing the on-resistance of the shunting devices.

Claims16

Dependent claims

An integrated circuit having an Electrostatic Discharge (ESD) circuitry comprising:

a plurality of pads, wherein each of the plurality of pads is coupled to a first bus, a second bus, and a third bus;
a plurality of pull-up circuits, wherein each of the plurality of pull-up circuits is coupled to each of the plurality of pads and the third bus;
a plurality of shunting circuits, wherein:
each of the plurality of pads is coupled to at least one of the plurality of shunting circuits via the first bus;
the plurality of shunting circuits operate in parallel in response to an ESD event on at least one of the plurality of pads to provide ESD protection for the plurality of pads;
and
at least one of the plurality of shunting circuits is coupled to the first bus, a fourth bus and the second bus;
and
a trigger circuit comprising a transient detector circuit, said trigger circuit having a first terminal coupled to each of the plurality of pads via the third bus, a second terminal coupled to at least one of the plurality of shunting circuits via the fourth bus, and a third terminal coupled to the second bus.

6 more elements

Dependencies are inferred from the claim text.

Electrostatic discharge protection circuitry and method of operation

Life of this patent

Electrostatic discharge protection circuitry and method of operation

Life of this patent

Abstract

Claims16