Calibration method for D=A converter and linearity correction

摘要

The calibration method involves generating a calibration signal having at least one frequency component using a digital oscillator (26) and an ultra-linear A/D converter. The calibration signal is then processed in the D/A converter (20) used in calibration mode to provide an analog signal. A frequency component of the analog signal produced from the calibration signal by non-linearity is detected to generate a compensation coefficient. In conversion mode, the D/A converter receives a digital signal which is compensated by the compensation coefficient to produce a distorted digital signal which is then converted to produce an analog signal having reduce distortion.