Patent ID: 7777527

Claim:
A phase detection apparatus comprising: a pulse generation unit generating a first pulse signal on an edge of an input pulse signal, and a second pulse signal based on an edge of a reference pulse signal having a predetermined phase; and a detection unit detecting a phase difference between the first pulse signal and the second pulse signal from the pulse generation unit; wherein the pulse generation unit comprises: a first pulse generator generating the first pulse signal synchronized with a rising edge of the input pulse signal; and a second pulse generator generating the second pulse signal synchronized with a rising edge of the reference pulse signal; wherein the first pulse generator comprises: a first inverter inverting a signal level of the input pulse signal; a first delay delaying the input pulse signal whose signal level is inverted by the first inverter by a predetermined amount of time; and a first AND gate performing an AND operation of the signal level of the input pulse signal and a signal level of the delayed input pulse signal by the first delay, and the second pulse generator comprises: a second inverter inverting a signal level of the reference pulse signal; a second delay delaying the reference pulse signal inverted whose signal level is inverted by the second inverter by a predetermined amount of time; and a second AND gate performing an AND operation of the signal level of the reference pulse signal and a signal level of the delayed reference pulse signal by the second delay.