To provide an amplifier circuit capable of simplifying a circuit.
An amplifier circuit 100 comprises: PNP transistors Q1 abd Q4; NPN transistors Q2 and Q3; and a bias circuit 20. An input signal is input into each of the base of the PNP transistor Q1 and the base of the NPN transistor Q2. The emitter of the PNP transistor Q1 and the emitter of the NPN transistor Q3 are connected to each other, and the collector of the PNP transistor Q1 is connected to a first potential. The collector of the NPN transistor Q2 is connected to a second potential that is the same as or different from the first potential, and the collector of the NPN transistor Q3 is connected to a constant power supply V1 line. Also, the collector of the PNP transistor Q4 is connected to a constant power supply V2 line, and the bias circuit 20 is connected between the base of the NPN transistor Q3 and the base of the PNP transistor Q4.
KITAGAWA NORIMASA
SEKIYA MAMORU
SHIMAZAKI NAOFUMI
