DIFFERENTIAL AMPLIFIER CIRCUIT AND METHOD FOR REDUCING THERMALLY INDUCED OFFSETS CAUSED BY LARGE DIFFERENTIAL SIGNALS

摘要

An amplifier includes a differential amplifier (10) having an input stage (20) for amplifying a differential input signal (Vin), and an output stage (6) coupled to the input stage (20) for producing and output signal (Vout). The input stage (20) includes main input circuitry (20A) for amplifying small-signal values of the input signal (Vin) and alternative input circuitry (20B) for amplifying the input signal (Vin) during conditions which cause thermal imbalance in the main input circuitry (20B). The input stage (20) includes switching circuitry (12) for coupling the input signal (Vin) to the main input circuitry (20A) during normal small-signal operating conditions and to the alternative input circuitry (20A) during large-signal operating conditions that cause thermal imbalance in the main input circuitry (20B).