Provided is a time-to-digital converter. The time-to-digital converter includes several delay circuits, an adder configured to count outputs of the delay circuits, and a least significant bit (LSB) truncation circuit configured to truncate a predetermined number of LSBs from a result output by the adder. The time-to-digital converter is configured to determine a time interval between a start signal and a stop signal within one cycle of a clock having a predetermined period.