Differential amplifier device, 2-stage amplifier device, and analog/digital converter device

摘要

A differential amplifier device is disclosed wherein the device comprises a differential amplifier circuit, a load circuit connected to the differential amplifier circuit; and a change-over switch connected to the load circuit for changing a gain of the differential amplifier circuit by switching between a full load where a whole of the load circuit is set to be the load of the differential amplifier circuit and a partial load where a part of the load circuit is set to be the load of the differential amplifier circuit, wherein the load circuit is configured to amplify an input signal and an output signal of the differential amplifier circuit in the full load. <IMAGE>