Short circuit and over-voltage protection for a data bus

摘要

An apparatus for protecting a device against an over-voltage condition that is in excess of its breakdown voltage includes a detector for detecting the over-voltage condition and a protection circuit for protecting the device in response to detection of the over-voltage condition. The protection circuit may include a transmission gate and a PMOS transistor for producing a protection signal. The protection signal may be applied to a gate and/or a drain and/or a source and/or a well of the device such that a voltage across the device does not exceed the breakdown voltage. The protection signal may be derived from the over-voltage condition independent of whether a supply of power to the device is present.