In described examples, a storage cell ring includes circularly coupled storage cells. Each storage cell includes a respective capacitor for generating a respective integrated voltage responsive to a respective duration a respective storage cell is selected, a respective thresholding converter for generating a respective thresholded signal for indicating whether the respective integrated voltage has crossed a threshold, and respective selection circuitry configured to generate a respective select signal responsive to select signals generated by a respective adjacent storage cells. The ring is coupled to an analog quantifier for generating a conversion value responsive to the generated respective integrated voltage and a respective select signal. The ring is coupled to a loop counter for generating a loop count value responsive to changes of values of at least some of the respective thresholded signals. The conversion value and the loop count value can comprise a time measurement.