| 摘要 |
The present invention relates to a circuit and a method for automatic common-mode rejection calibration in a differential conversion system and unbalance compensation for balancing the operation point of a circuit in the signal path and for enhancing the common-mode rejection. The circuit for automatic common-mode rejection calibration in a differential conversion system comprises an analog input stage for an analog input signal (101), an analog-digital-converter (106) for converting an analog signal (107) into its digital representation (108), a digital block (105) arranged to adapt said digital representation (108) of a portion of a DC offset of said analog input signal (101) in accordance with whether said analog input signal (101) is in a predetermined input range of said analog-digital-converter (106), and a digital-analog-converter (103) arranged in a feedback path (102) from said digital block (105) to subtraction means (111) of said analog input stage for converting a digital signal (104) into an analog output signal (109), wherein said analog output signal (109) is subtracted from said analog input signal (101) resulting in said analog signal (107). |
