HIGH VOLTAGE ESD PROTECTION FEATURING PNP BIPOLAR JUNCTION TRANSISTOR

摘要

A protection circuit is disclosed that protects a semiconductor device from damage due to an electrostatic discharge. One such protection circuit comprises a vertical pnp hetero-junction bipolar transistor (HBT) connected between terminals such as supply terminals of the device, configured to conduct during an electrostatic discharge. The protection circuit also comprises a trigger circuit, such as a transient activated RC circuit connected between the terminals to detect the electrostatic discharge and control the transistor based on the detected electrostatic discharge. A Darlington transistor pair in the trigger circuit can be used to multiply the effective capacitance and HBT drive current. The HBT transistor absorbs energy from the electrostatic discharge and clamps the over-voltage across the terminals. The protection circuit may also be used across other I/O terminals of the device.