Differential amplifier

A differential amplifier is constituted of first emitter-follower transistors, second emitter-follower transistors, and amplification transistors whose bases are alternately connected to the emitters of the second emitter-follower transistors and whose collectors are connected to the emitters of the first emitter-follower transistors, as well as emitter resistors and constant current sources, whereby it is possible to reduce distortions of output signals in response to large-amplitude input signals, thus ensuring high-speed operation. It is possible to further incorporate base-grounded transistors and diodes, by which substantially the same collector-emitter voltage is applied to the emitter-follower transistors and amplification transistors, thus achieving the same power consumption and the same temperature variations with respect to these transistors. This reduces the nonlinear amplification error due to temperature differences of transistors, thus achieving flat gain characteristics in broad ranges of frequencies.