Differential amplifier, particularly of the cascode type

An amplifier having a differential stage comprising a main pair of input transistors and an auxiliary pair of input transistors coupled between a supply terminal and a reference terminal, the interconnected emitters of the main pair of input transistors being driven by an emitter current source which is also connected to the reference terminal, and the interconnected emitters of the auxiliary pair of input transistors being driven in a similar way, means connecting bases of the transistors of the main pair to corresponding bases of the transistors of the auxiliary pair, said bases forming input terminals for input voltages whose difference defines a differential input voltage, a part of the collector currents of the transistors of the auxiliary pair being used for a suitable summation with the collector currents of the transistors of the main pair to derive output currents of the differential stage which increase the linearity of said output currents in comparison with the differential input voltage, characterised in that the differential stage comprises a pair of cascode transistors whose collector-emitter paths are arranged as loads in the collectors of the transistors of the main pair, and whose bases are interconnected and connected to a fixed intermediate reference voltage, and said summation is effected by means of two resistive bridges connected between a supply voltage and each of the respective collectors of the transistors of the main pair of input transistors, the collectors of the transistors of the auxiliary pair being connected to respective nodes of respective resistive bridges.