Patent ID: 8324966

Claim:
An apparatus, comprising: a first stacked differential amplifier stage having a non-inverted input, an inverted input, a non-inverted output and an inverted output, the amplifier stage comprising: a first amplification subcircuit; a second amplification subcircuit; a third amplification subcircuit; and a fourth amplification subcircuit, wherein the first and second amplification subcircuits are arranged as a first differential amplification block, and the third and fourth amplification subcircuits are arranged as a second differential amplification block; and a bias circuit for powering the first and second differential amplification blocks, the bias circuit configured to operate as a current source for each of the first and second differential amplification blocks, wherein each amplification subcircuit is configured to receive an input signal as an input and to generate an amplified version of the input signal as an output, and wherein the first and second amplification subcircuits are electrically powered in the first differential amplification block and the third and fourth amplification subcircuits are electrically powered in the second differential amplification block such that the first and second amplification subcircuits operate from a first portion of a power supply voltage and the third and fourth amplification subcircuits operate from a second portion of the power supply voltage, wherein the second portion is different from the first portion; wherein the inputs of the first and fourth amplification subcircuits are electrically connected to the inverted input, and the inputs of the second and third amplification subcircuits are electrically connected to the non-inverted input, and wherein the outputs of the first and fourth amplification subcircuits are electrically connected to the one of the non-inverted output or the inverted output, and the outputs of the second and third amplification subcircuits are electrically connected to the other one of the inverted output or the non-inverted output.