Patent ID: 7304540

Claim:
A current feedback circuit, applied in a source follower, the source follower comprising a transistor having a first electrode, a second electrode, and a third electrode, the first electrode receiving an input signal, the second electrode outputting an output signal according to the input signal, a current of the source follower flowing through the transistor, the current feedback circuit comprising: a first impedance, coupling to the third electrode to form a node, wherein the current of the source follower flows through the first impedance and the node outputs an error voltage; a comparator, coupled to the first impedance, for outputting a reference current according to the error voltage and a reference voltage; and an adder, for adding an active current and the reference current and thereby outputting an added current; wherein the source follower comprises: a current source, for generating the active current; and a current mirror, coupled to the adder and the transistor, for controlling the current of the source follower according to the added current.