DIFFERENTIAL AMPLIFIERS

A differential amplifier is disclosed which consists of two constant current sources I.sub.1, I.sub.2, one end of each of which is connected to a power supply terminal 4, a pair of differential transistors consisting of two FETs M.sub.1, M.sub.2, each of the gates of which is connected to singnal input terminals 1 and 2, respectively, and both the sources of which are connected to the other end of the current source I.sub.2, a current-mirror circuit consisting of FETs M.sub.3, M.sub.4, wherein in the FET M.sub.3 a connection point common to the gate and the drain is connected to the other end of the current source I.sub.2 and the source is connected to a power supply terminal 5, and wherein in the FET M.sub.4 the gate is connected to the connection point, the source is connected to power supply terminal 5, and the drain is connected to the drain of the FET M.sub.1, and an FET M.sub.5 wherein the gate is connected to the drain of the FET M.sub.4, the source is connected to the power supply terminal 5, and the drain is connected to the drain of the FET M.sub.5, wherein the difference between the voltages of two input signals inputted to the signal input terminals 1, 2 is amplified and outputted from the signal output terminal connected to the drain of the FET M.sub.5, thereby an improved differential amplifier which has a large voltage gain, and is adaptable to a high-precision signal processing circuit can be provided.