| 摘要 |
The present invention relates to Method for compensating DC offset in a signal path comprising a plurality of stages, wherein for each stage a fine DC compensation is performed by introducing a fine DC compensation signal into the signal path of said stage by means of the compensation analog to digital converter, wherein said fine DC compensation signal is determined by setting the total gain of said stage to a value that equals the product of a first total gain of the preceding stage(s) and a first gain of said stage, setting at least two different DC compensation signals for said stage and measuring a DC residual signal at the output of the signal path for each of the two different DC compensation signals in order to determine a first linear relationship between DC compensation signal and DC offset residual at the output of said signal path, setting the total gain of said stage to a value that equals the product of a second total gain of the preceding stage(s) and a second gain of said stage, setting at least two different DC compensation signals and measuring a DC residual signal at the output of the signal path for each of the two different DC compensation signals in order to determine a second linear relationship between DC compensation value and gain, and determining an interception point of said first linear relationship and said second linear relationship, wherein the DC compensation signal of said interception point is the fine DC compensation signal. |
