A sensing device that is configured to determine a depth result based on time-of-flight value is introduced. The sensing device includes a delay locked loop circuit, a plurality of time-to-digital converters, a multiplexer and a digital integrator. The delay locked loop circuit is configured to output a plurality of delay clock signals through output terminals of the delay locked loop circuit. The plurality of time-to-digital converters include a plurality of latches. The multiplexer is configured to select a sub-group of m latches among the latches of the plurality of time-to-digital converters to be connected to the output terminals of the delay locked loop circuit according to a control signal. The digital integrator is coupled to the plurality of time-to-digital converters and is configured to integrate digital outputs generated by the time-to-digital converters in each of n cycles to generate n raw data frames, wherein m and n are natural numbers, and the n raw data frames are used to generate the depth result.