PSEUDO IMPEDANCE CIRCUIT

PROBLEM TO BE SOLVED: To provide a pseudo impedance circuit which can secure a linear impedance characteristic in regard to a pseudo impedance circuit which falsely rises the input impedance according to the frequency by controlling the base voltage of plural transistors according to the input voltage. SOLUTION: This impedance circuit consists of a PNP transistor TR Q1 which outputs the collector current according to the relevant input signal with its base current controlled according to the input signal, a PNP TR Q2 which controls the collector current of the TR Q1 according to the base current of the TR Q1 with its emitter connected to the collector of the TR Q1, and an NPN TR Q3 whose base is connected to the collector of the TR Q2 with its base connected to the collector of the TR Q2 respectively.