| 摘要 |
PROBLEM TO BE SOLVED: To provide a local oscillator eliminated in a TDC (time-to-digital converter) without increasing power consumption.SOLUTION: The local oscillator includes: a digitally-controlled oscillator for outputting an oscillating signal having a frequency N times as large as an oscillating frequency according to an oscillator control word; a frequency divider for performing the 1/N frequency division of the oscillating signal, and outputting a 2N phase clock; a first flip-flop for latching the clock with the reference signal, and outputting the resultant as first phase information; a variable delay circuit for delaying the reference signal and outputting the resultant as a delay reference signal; a second flip-flop for latching the clock with the delay reference signal, and outputting the resultant as second phase information; a delay control means for controlling a delay amount of the variable delay circuit; a data conversion means for outputting an integer oscillator phase based on the first and second phase information; and an adder for adding the integer oscillator phase and the fractional oscillator phase, and outputting the added value as third phase information. |
