Patent ID: 7525365

Claim:
An apparatus that comprises: an amplifier circuit that comprises: a first portion and a second portion that can be operated in a first configuration and operated in a second configuration, wherein said first portion and said second portion each comprises an input transistor, a current source transistor, a mirror transistor, and a cascode transistor, wherein said first portion and said second portion of said amplifier circuit operate in said first configuration during a first period of time to obtain a first value of offset voltage, and wherein said first portion and said second portion of said amplifier circuit operate in said second configuration during a second period of time to obtain a second value of offset voltage that has a polarity that is opposite to that of said first value of offset voltage; and circuitry comprising a capacitor and an inductor, the circuitry operable to average said first value of offset voltage and said second value of offset voltage to obtain an average value of offset voltage.