ANALOG INTEGRATED CIRCUIT FOR BASEBAND IN DIRECT CONVERSION RECEIVER AND DC OFFSET ELIMINATING METHOD OF THE SAME

摘要

An analog integrated circuit for baseband in a direct conversion receiver and a method for eliminating DC(Direct Current) offset are provided to reduce the frequency of all switching generation of DCOC(DC Offset Cancellation) when a gain is changed, thereby preventing the quality of a reception signal from being degraded. An analog integrated circuit for baseband in a direct conversion receiver includes a first DC offset cancellation unit and a second DC offset cancellation unit. The first DC offset cancellation unit(32a) is operated by two operation modes of a normal mode and a fast mode and receives analog baseband signal and outputs a signal in which DC offset is eliminated according to mode control and gain control. The second DC offset cancellation unit(32b) is operated by two operation modes of a normal mode and a fast mode and receives an output signal of the first DC offset cancellation unit and outputs a signal in which DC offset is eliminated according to mode control and gain control.