Integrated circuit having high voltage detection circuit

摘要

A high voltage detection circuit implemented in an integrated circuit which is switchable between a normal operation mode and an alternative operation mode and having contact pads for electrically connecting the integrated circuit to an external environment. One of the pads functions to provide an interface between an external environment and the integrated circuit for signals having a maximum voltage magnitude, relative to a circuit common, when the integrated circuit is in the normal operation mode. The one pad further functions to receive an external test mode signal which will cause the integrated circuit to switch to the test mode of operation, with the test mode signal having a voltage magnitude which is greater than that of maximum voltage magnitude. The detection circuit includes a first MOS transistor having either the gate or source coupled to the one pad and a second MOS transistor having a source and drain connected in series with the drain and source of the first transistor. An output circuit is included having an input connected to a first node intermediate the first and second transistors for providing an output when a voltage at the first node exceeds a predetermined trip point.