Patent ID: 8125273

Claim:
An apparatus comprising: a first supply rail; a second supply rail; an driver output terminal; a first differential pair that receives an input signal; a level shifter that is coupled to the first differential pair; a second differential pair that is coupled to the level shifter and a common node; a voltage follower that is coupled across the second differential pair and that is coupled to the driver output terminal; a third differential pair that is coupled to the common node; a first resistor that is coupled between the first supply rail and each transistor of the third differential pair; a second resistor that is coupled to the first supply rail; an amplifier having an first input terminal, a second input terminal, and an output terminal, wherein the first input terminal is coupled to the first resistor, and wherein the second input terminal is coupled to the second resistor, and wherein the output terminal is coupled to each transistor of the first differential pair; and a current source that is coupled between the second input terminal and the second supply rail.