Patent ID: 7888998

Claim:
An analog error amplifier, comprising: an amplifier circuit including an input signal input, a bias signal input, and an output signal output, and wherein the amplifier circuit produces an output signal on the output signal output in response to an input signal on the input signal input and a bias signal on the bias signal input such that the output signal represents a difference between the input signal and the bias signal; and a replica bias circuit including a reference signal input and a bias signal output, wherein the replica bias circuit produces a bias signal on the bias signal output in response to a reference signal on the reference signal input and drives the bias signal to be equal to the reference signal; and wherein the bias signal output of the replica bias circuit is connected to the bias signal input of the amplifier circuit, such that the amplifier circuit and replica bias circuit together produce the output signal in response to the input signal and the reference signal such that the output signal represents a difference between the input signal and the reference signal.