Abstract: First and second current mirror circuits are provided to the first and second amplifying transistors, respectively. The output current paths of current mirror circuits constitute output current terminals, respectively, and the reference input current paths are connected to the collectors of the first and second transistors, respectively. The first current mirror circuit comprises third and fourth transistors and the second current mirror circuit comprises fifth and sixth transistors. The base of the third transistor of the first current mirror circuit and the base of the fifth transistor of the second current mirror circuit are connected to first and second reference potentials, respectively. The base of the fourth transistor of the first circuit and the base of the sixth transistor of the second circuit are connected to the collectors of the first and second transistors, respectively.

Abstract: A composite transistor circuit which comprises a first current mirror circuit whose reference current circuit is connected in series to the collector of an input transistor, and a second current mirror circuit whose reference current circuit is connected between the output current circuit of the first current mirror circuit and the emitter of the input transistor.