LOW DISTORTION CURRENT MIRROR

A current mirror implemented preferably in MOS technology provides low total harmonic distortion and high output impedance and maintains the input signal within one Vgs of the supply voltage source. For an input signal having DC and AC components I and i, a constant curent of 2I is fed to the input terminal. A transistor couples the input terminal to the output terminal. The difference of the constant current and the input current is the output current I-i which passes through the transistor to the output terminal. An amplifier having its input connected to the input terminal and its output fed back to the gate or base of the transistor helps maintain the input terminal at a constant voltage.