A high voltage linear current sense integrated circuit includes a differential amplifier circuit that can amplify a differential signal in the hundreds of millivolts near the power supply. In addition, a constant current using opposing minus temperature coefficient MOSFETs is provided. Accordingly, an op-amp circuit is provided with an input offset voltage which is constant and insensitive to temperature changes. A circuit for generating a current reference on the high side of the current sense IC also is provided.