Patent ID: 7522902

Claim:
A direct current (DC) offset compensation apparatus comprising: an offset detection block detecting a DC offset; an offset compensation block operating according to an output signal of the offset detection block; and an offset compensation amplifying block controlled according to an output signal of the offset compensation block, wherein the offset compensation block comprises: a counter counting polarities of DC offsets for a predetermined period using the output signal of the offset detection block; a controller comprising: a first mode unit operating a fast down-compensation mode for the DC offset; a second mode unit operating a regular down-compensation mode for the DC offset; a third mode unit operating a fast up-compensation mode for the DC offset; a fourth mode unit operating a regular up-compensation mode for the DC offset; and a control device controlling the execution of one selected among the first to fourth mode units based on a value counted by the counter; and a register storing data to control the offset compensation amplifying block based on the one mode unit determined by the controller.