JPS6434094A - Loop forming circuit by junction type field effect transistors - Google Patents

Abstract

PURPOSE:To prevent the zero cross distortion of an output voltage-current characteristic by equipping two junction type field effect-transistors. CONSTITUTION:A constant current source 5 is composed of a junction type magnetic field efficiency transistor 3 and a constant current value setting circuit 7, and a constant current source 6 is composed of a junction type field effect transistor 4 and a constant current value setting circuit 7. As long as the potential of a terminal 1 to a terminal 2 is a positive potential, an reverse bias is given to a junction type field effect transistor 2, and a between drain sources voltage VDS4 goes to almost zero. On the other hand, the junction type field effect transistor 3 forms the constant current source by setting a resistance 10 to a source resistance, and the transistor goes to be equivalent to a circuit to connect a serial resistance 11 to the constant current source 5. Consequently, the output voltage-current characteristic of the constant current source 5 goes to the output voltage-current characteristic of the circuit. Namely, by composing the constant current sources 5 and 6 or the junction type field effect transistors, the output voltage-current characteristic goes to a characteristic which does not have zero cross distortion.