A monolithic interface circuit for providing a voltage, from a control circuit supplied by a supply voltage referenced to a reference voltage, to a terminal likely to be at a high voltage with respect to the reference voltage, comprising a high-voltage N-channel MOS transistor having its gate intended to receive a control signal referenced to the reference voltage and having its source intended to be connected to the reference voltage, and a high-voltage PNP transistor having its base connected to the drain of the MOS transistor, having its emitter intended to receive the supply voltage and having its collector intended to provide a voltage to the terminal likely to be at a high voltage.