US Patent 7911262 External compensation for input current source

An integrated circuit includes: a pre-driver stage, coupled to an external supply voltage, for controlling the final driver stage; a final driver stage, coupled to the pre-driver stage and the external supply voltage, for providing an output voltage; a compensation circuit, coupled to the pre-driver stage, for providing a bias voltage to the pre-driver stage that compensates for variation in the external supply voltage, to control current through the pre-driver stage; and a bias circuit, coupled to the external supply voltage and the compensation circuit, for providing a bias voltage as an input to the compensation circuit.