Patent ID: 8174324

Claim:
A digital phase detector, comprising: a quantization unit configured to quantize a frequency of a reference signal to generate reference delay information and reference integer phase information, and configured to quantize a frequency of an oscillation signal to generate oscillation delay information and oscillation integer phase information; a first conversion unit configured to convert the frequency of the reference signal into reference frequency information based upon the reference delay information and the reference integer phase information; a second conversion unit configured to convert the frequency of the oscillation signal into oscillation frequency information based upon the oscillation delay information and the oscillation integer phase information; and a calculation unit configured to convert the reference frequency information into first phase information, configured to convert the oscillation frequency information into second phase information, and configured to output a digital phase difference between the first phase information and the second phase information, wherein the first conversion unit generates reference fraction phase information based upon the reference delay information, and generates reference phase information by adding the reference fraction phase information to the reference integer phase information, wherein the first conversion unit converts the frequency of the reference signal into the reference frequency information using: dF REF ⁡ ( n ) = F OSC F REF = CNT R ⁡ ( n ) - CNT R ⁡ ( n - 1 ) - 1 + fr R ⁡ ( n ) + 1 - fr R ⁡ ( n - 1 ) where dF REF (n) denotes reference frequency information detected at (n)th rising edge, F OSC denotes a frequency of a clock signal, F REF denotes a frequency of a reference signal, CNT R (n) denotes reference integer phase information outputted at (n)th rising edge, CNT R (n−1) denotes reference integer phase information outputted at (n−1)th rising edge, fr R (n) denotes reference fraction phase information outputted at (n)th rising edge, and fr R (n−1) denotes reference fraction phase information outputted at (n−1)th rising edge.