Patent ID: 8754708

Claim:
An operational amplifier, comprising: an input-stage circuit, receiving an input signal, and producing a control signal; a floating current mirror circuit, coupled to said input-stage circuit, and producing, a mirror current according to said control signal; and an output-stage circuit, coupled to said floating current mirror circuit, and producing a driving signal according said control signal and said mirror current; wherein when said operational amplifier is operating in the static mode, said output-stage circuit further produces a static current according to said mirror current; wherein said floating current mirror circuit comprises: a current source, used for producing a current; a current mirror unit, coupled to said current source, and producing said mirror current according to said current produced by said current source; a control device, coupled to said input-stage circuit and said current mirror unit, and controlling said current mirror unit to produce said mirror current according to said control signal; and a voltage control unit, coupled to said control device and said current mirror unit, and controlling said output-stage circuit to produce said driving signal or said static current according to said control signal.