PARALLEL FEEDBACK AMPLIFIER

PURPOSE:To improve power noise elimination capability of a parallel feedback amplifier and to economize a power supply device by providing a resistive element between a voltage source and an emitter of an input transistor(TR). CONSTITUTION:A resistor 12 or a constant current element (the resistance between two terminals of a constant current element is large) is inserted between an emitter of an input TR 5 and a voltage source 4, and a diode group 13 or an element having an equivalent constant voltage characteristic is connected in series between the emitter of the input TR 5 and ground. Thus, a resistance between the voltage source 4 and an output terminal 2 is increased while keeping a constant voltage characteristic at the emitter of the input TR 5. Thus, the power supply noise eliminating capability is improved, resulting that the power supply noise eliminating capability in the power supply is designed to be low and the power supply is formed inexpensively.