Input protection circuit for a semiconductor device

Abstract

A transient protection circuit (,) includes a resistor (,) having a first end adapted for connection to a first signal line (,) of a voltage supply (,) and a second opposite end connected to a voltage supply input (,) of an application circuit (,). In one embodiment, the resistor (,) defines an emitter (,) of a PNP transistor (,) having a floating base (,) and a collector (,) adapted for connection to a reference signal line (,) of the voltage supply (,). In an alternative embodiment (,′), the emitter (,) of the PNP transistor (,) is connected to the first end of the resistor (,). The transient protection circuit (,′) is preferably formed on a monolithic integrated circuit including the application circuit (,) wherein a semiconductor layer (,) defining the first input to the resistor (,) also defines a bond pad (,). The corners of the semiconductor layer (,) including those of the bond pad (,) are configured to equalize the electric field about the entire outer periphery of the semiconductor layer (,). The transient protection circuit (,′) is operable to protect the application circuit (,) from transient and other fault conditions associated with the voltage supply (,) including transient voltage spikes, load dump conditions, electrostatic discharge (ESD) events, reverse battery conditions and discharge events from an ignition coil secondary.