CURRENT LIMITING CIRCUIT

PURPOSE:To reduce the disturbance distortion caused by the inductance of a resistance or a substrate due to a load condition by providing a resistance for detection on the collector side of a power amplification element. CONSTITUTION:Bases of output transistors TRs TR1 and TR2 are connected as power sources for bias to power sources +Vcc1 and -Vcc2 through constant current sources A1 and A2, and a signal is supplied from an input signal terminal N to bases of both output TRs through a base bias power source BT1 of TRs TR1 and TR2. If currents of output TRs TR1 and TR2 are increased by short-circuit or the like of a load RL, voltages between both ends of resistances R1 and R2 for detection are increased. When VBEs of TRs TR5 and TR6 reach a value for turning-on, VBEs of TRs TR3 and TR4 are fixed by diodes D1 and D2 and TRs TR5 and TR6 and are limited to a certain current value. Consequently, emitter currents of TRs TR1 and TR2 are limited in the same manner as TRs TR3 and TR4.