Differential amplifier with bipolar transistors which is compatible with standard complimentary MOS (CMOS) technology

摘要

There is disclosed a differential amplifier which comprises bipolar transistors which may be produced using MOS technology and wherein the amplifier is particularly useful when the transistors have a poorly defined current gain. The amplifier includes a first pair of transistors having emitters connected in common and having bases forming the inputs to the differential amplifier. A second pair of transistors identical to the first pair are coupled such that the emitters and bases of said second pair are connected respectively to the emitters and bases of the first pair. The collectors of the second pair of transistors are connected to a current generator and to the input of a transconductance amplifier such that the transconductance amplifier causes the sum of the emitter currents of the first and second pairs of transistors to be controlled by the current supplied by the current generator.