SPADs detect photons of a return light pulse and output corresponding pulse signals. First and second counters, when enabled in response to phase measurement value, are configured to count the pulse signals. The phase measurement value is set for a subsequent iteration of the return light pulse in response to processing of first and second count values of the first and second counters, respectively, for a current iteration. If the first count value exceeds the second count value by more than a difference threshold limit, the phase measurement value is decremented for the subsequent iteration. Otherwise, the phase measurement value is incremented for the subsequent iteration. If the difference threshold limit is not satisfied, the phase measurement value may be maintained for the subsequent iteration, but one of the counters is preloaded for the subsequent iteration with a value equal to a magnitude of the difference between the count values.