Patent ID: 7893710

Claim:
An impedance matching device, comprising: a calibration circuit configured to generate impedance calibration codes for calibration of impedance; a code modification unit configured to modify the impedance calibration codes according to impedance setting information and output modified impedance calibration codes; and a termination impedance unit configured to terminate an interface node with impedance determined according to the modified impedance calibration codes, wherein, the termination impedance unit comprises: a plurality of first resistor units configured to be turned-on/off according to the modified impedance calibration codes when a termination operation is enabled; a second resistor unit configured to maintain an on-state when the termination operation is enabled; and one or more third resistor units configured to be turned-on/off according to the impedance setting information when the termination operation is enabled, wherein the first to third resistor units are connected in parallel to the interface node.