Combination driver-summing circuit for rail-to-rail differential amplifier

摘要

A combination driver/summing circuit for rail-to-rail operation of a differential amplifier includes a differential amplifier input stage that amplifies an input signal and a current control circuit that regulates the operating currents through the active elements of the differential amplifier input stage. A summing circuit divided into first and second segments and supplied with current from a single common floating current source combines internal currents supplied by the differential amplifier input stage. A class A-B driver/output stage is coupled to the summing circuit to derive at least one output signal representative of the input signal and which is operative over nearly the full rail-to-rail supply voltage range.