| 摘要 |
PURPOSE:To adjust linearity without generating SN deterioration in a D/A converter on the output side by applying a data offset to digitally processed digital signal data and then D/A converting the data. CONSTITUTION:An analog input is A/D-converted by an A/D converter 10 and digitally processed by a digital signal processing part 12 so that frequency characteristics are changed or a component corresponding to a DC is cut off. A data offset component is added to the processed signal by a mixer 14 and the added signal is D/A converted by a D/A converter 16 and then outputted. A data offset value is set so that the most significant bit of an input to the D/A converter 16 is not almost driven within the amplitude range of dark noise transmitted from the digital signal processing part 12. Even it the linearity based upon the most significant bit is adjusted by the D/A converter 16, the increase of noise is not generated, so that the linearity can be adjusted to the best state while preventing the SN ratio from being deteriorated.
|
