US Patent 7990664 Electrostatic discharge protection in a field programmable gate array

An ESD protection circuit is integrated into the core of an FPGA in a distributed fashion coupling the bodies of one or more transistors to the power supply pin and/or the ground pin of the FPGA. The ESD protection circuit includes one or more positive discharge paths and one or more negative discharge paths. In the case of a positive ESD event, the positive discharge paths are on and the negative discharge paths are off. In the case of a negative ESD event, the positive discharge paths are off and the negative discharge paths are on. In either event, the bodies of the transistors track the voltages at the power supply pin and/or the ground pin to protect the core from being by damaged by electrostatic discharge.