Abstract: An uncalibrated converter element in an analog-digital converter may be replaced with two or more smaller elements having an effective total net value that is equal to that of the uncalibrated converter element. In an exemplary case where the element is capacitor, one or more of these smaller capacitors may be independently calibrated by switching the smaller capacitor between two voltages, such as a reference voltage and ground, and then calculating a difference of corresponding digital output codes generated by the backend ADC with previously calibrated capacitors associated with lesser significant bits. The total capacitance of the uncalibrated capacitor may be apportioned between the smaller capacitors so that the individual maximum charge contribution of each smaller capacitor to the converter output together with any expected manufacturing variance does not exceed the aggregated contribution of the previously calibrated capacitors.

Abstract: A tracking module that tracks the operation of a digital-to-analog converter (DAC). The DAC tracking module may be included on-chip with a DAC, and be formed with similar circuit components as a DAC. The DAC tracking circuit may output a signal indicating that the DAC within a SAR ADC has settled to an approximate value during each bit conversion. A differential solution is also provided. Power may be optimized because optimal conversion speed may be achieved, and a comparator within the DAC may be turned off or placed in a standby mode at the end of bit conversions, and before the next conversion cycle in response to the signal output by the DAC tracking module.