Patent ID: 6882295

Claim:
A differential comparator having positive and negative inputs and positive and negative outputs, comprising: a current source for driving current from a supply to a common node; a differential pair of transistors having one side of the source/drain paths thereof tied together and to said common node and the other side of the source/drain paths thereof for each of the transistors in said differential pair interfaced to the positive and negative outputs, respectively for applying drive thereto; a first resistor disposed between said positive output and a supply reference opposite in polarity to the supply; a second resistor disposed between said negative output and said supply reference; the gate of the one of the transistors in said pair associated with said positive output connected to the negative input, and the gate of the other of the transistors in said pair connected to the positive input; the current through said current source defining a common mode bias; and a bias circuit for controlling the voltage on a first output and a second output at the first and second resistors to be at a common mode voltage that is controlled by an external bias voltage when the positive and negative inputs are at substantially the same voltage.