Patent ID: 6265929
Filing Date: 2001-07-24
Classification: G05F

Abstract:
A rail-to-rail output stage that produces an output signal resulting in a load current in a load in response to an input signal received at a signal input, comprising:an output driver, controlled by said input signal, that at least partially controls said load current in said load, said output driver comprising a transistor having a control terminal responsive to the input signal, and that has a square-law factor K (amperes per squared volt);a complementary subcircuit, controlled by said input signal and a bias voltage, that comprises two transistors of different polarity, that produces a subcircuit current, and that has a combined square-law factor Kc (amperes per squared volt); anda current mirror, controlled by said subcircuit current, that at least partially controls said load current in said load and that has a current ratio M,wherein said subcircuit and said current mirror produce a first non-linear component in said output signal that cancels a second non-linear component in said output signal produced by said output driver, and wherein said output driver, said subcircuit, and said current mirror are sized so that said square-law factor K substantially equals said square-law factor Kc multiplied by said current ratio M.