A tracking analog-to-digital converter “ADC” with a self-controlled variable clock comprises: a digital register; a digital-to-analog converter “DAC” coupled to said digital register providing an analog feedback signal; a comparator coupled to an analog input signal and said analog feedback signal and providing a comparison signal based on a comparison between said analog input signal and said analog feedback signal, said comparison signal being coupled to the digital register; a means for determining comparator readiness to determine if said comparator is ready, indicating that said comparison signal can be reliably read, said means for determining comparator readiness further comprising a determination of a comparison ready indicator; a means for clocking to generate a clock signal to drive said digital register in response to said means for determining comparator readiness determining that said comparator is ready; and said digital register being configured to count in response to said clock signal based on said comparison signal of the comparator.