Abstract
We have been researching and developing a digital calibration technique for a two-stage single-ended cyclic ADC suitable for a 33-Mpixel 120-fps 8K Super High-Vision CMOS image sensor to improve the nonlinearity of the ADC. The technique needs to accurately determine error coefficients that define the quantity of errors caused in the ADC. However, the error coefficients have so far been determined on the basis of estimation from the design parameters of the ADC. Therefore, we proposed a new ADC operation and signal processing scheme to determine them accurately and dynamically by measuring the ADC output code including the errors and verified its effectiveness for precise and dynamic digital calibration by performing a preliminary experiment using the ADC test circuit.
