A new digital background calibration technique for pipelined ADC

A digital background calibration technique to compensate for the finite opamps dc gain in pipelined analog-to-digital converters is presented. By transforming the ADC and measuring the gain ratios between different configurations, a background calibration is possible without interrupting the ADC operation or injecting a calibration signal. A modified multiplying digital-to-analog converter (MDAC) is proposed. This new MDAC allows the ADC to toggle between different configurations to create a reference signal used for the calibration. Simulations results prove the effectiveness of this new method.