Technique for protecting integrated circuit devices against electrostatic discharge damage
AssigneeAltera Corporation
InventorsCheng H. Huang, Chiakang Sung, John Costello
Life of this patent
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Abstract
A technique for providing ESD protection for integrated circuit devices with multiple power and/or ground buses is provided. The technique involves using a clamping device that is capable of handling both positive and negative ESD pulses to clamp each power bus, ground bus, and I/O pad within a device to a respective one of the ground buses. Without resorting to exhaustive cross-clamping, this arrangement provides a discharge path for an ESD pulse applied across any combination of power buses, ground buses, and I/O pads during an ESD event.
Claims23
An integrated circuit device comprising:
- a plurality of circuit blocks connected to a plurality of power buses;
- a plurality of existing ground buses internal to the integrated circuit device configured to provide a plurality of electrical grounds for the plurality of circuit blocks, wherein one of the existing ground buses internal to the integrated circuit device is a multi-purpose clamp bus;
- and
- a plurality of clamp circuits, wherein each power bus is connected to the clamp bus through a respective one of the clamp circuits associated with that power bus, and each existing ground bus other than the clamp bus is connected to the clamp bus through a respective one of the clamp circuits associated with that existing ground bus.
For use on an integrated circuit device fabricated on a substrate and having a plurality of power buses and a plurality of existing ground buses internal to the integrated circuit device, a method for providing electrostatic discharge protection, comprising:
- configuring a respective one of the plurality of existing ground buses internal to the integrated circuit device as a multi-purpose ground bus;
- providing a plurality of clamp circuits;
- and clamping each power bus to the multi-purpose ground bus through a respective one of the clamp circuits associated with that power bus, and further clamping each existing ground bus other than the multi-purpose ground bus to the multi-purpose ground bus through a respective one of the clamp circuits associated with that existing ground bus.
An integrated circuit device comprising:
- a plurality of circuit blocks connected to a plurality of power buses;
- a plurality of input/output pads;
- an existing ground bus internal to the integrated circuit device configured as a multi-purpose ground bus;
- and
- a plurality of clamp circuits, wherein each power bus is connected to the existing ground bus internal to the integrated circuit device through a respective one of the clamp circuits associated with that power bus, and wherein a subplurality of the input/output pads within the plurality of input/output pads are connected to the existing ground bus internal to the integrated circuit device through the clamp circuits associated with the subplurality of input/output pads.
Dependencies are inferred from the claim text.