Patent ID: 8330446

Claim:
A calibration apparatus, comprising: a first circuit, arranged for generating a reference voltage with respect to a first circuit element according to a reference current flowing to the first circuit element; a second circuit, arranged for generating an output voltage according to a tunable current; and an adjusting circuit, coupled to the first circuit and the second circuit, for adjusting the tunable current to a target current value according to the reference voltage and the output voltage, wherein the adjusting circuit comprises: a search unit, for performing a search according to a comparison result of the reference voltage and the output voltage to thereby determine a control setting; and a control unit, coupled to the search unit, for generating a control signal to the second circuit according to the control setting, wherein the search unit operates according to a clock signal, and after the search unit adjusts the control setting, the search unit stops adjusting the control setting according to the comparison result for a predetermined number of clock cycles of the clock signal.