US Patent 9450402 Electrostatic discharge protection circuitry with reduced capacitance

Integrated circuits with electrostatic discharge (ESD) protection circuitry are provided. Integrated circuits may include input-output pins that are coupled to the ESD protection circuitry. The ESD protection circuitry may include diode circuits, a control circuit, and a power clamp circuit. Each diode circuit may have a first terminal that is coupled to a respective input-output pin and a second terminal that is coupled to a shared ESD control line. The control circuit may supply a boosted voltage onto the control line to reverse bias the diode circuits during normal operation while the power clamp is turned off. During an ESD event, the power clamp may be turned on to sink current from the diode circuits. The power clamp may include a transistor having a substrate that is forward biased to improve transistor drive strength during the ESD event and that is reverse biased to reduce leakage during normal operation.