Patent ID: 7295071

Claim:
A two-stage amplifier circuit fabricated in a dual gate oxide fabrication process having thick gate oxide devices as high voltage MOS transistors and thin gate oxide devices as low voltage MOS transistors, the two-stage amplifier circuit comprising: a first stage amplifier comprising a pair of differential input terminals coupled to a first pair of input transistors for receiving a first pair of differential input voltages referenced to a first input common mode voltage and a pair of differential output terminals providing a first pair of differential output voltages referenced to a first output common mode voltage; and a second stage amplifier comprising a pair of differential input terminals coupled to a second pair of input transistors for receiving the first pair of differential output voltages of the first stage amplifier and a pair of differential output terminals providing a second pair of differential output voltages referenced to a second output common mode voltage, wherein the first and second pair of input transistors are low voltage MOS transistors and the first output common mode voltage has a voltage value that is minimized to maximize the voltage swing of the second pair of differential output voltages.