US Patent 7949081 Phase detecting circuit and clock generating apparatus including the same

A phase detecting circuit includes a first node that outputs a pull-up control signal, a second node that outputs a pull-down control signal, an initializing unit that initializes voltage levels of the first and second nodes in response to a pre-charge signal, a data input unit to which receives a receiver data, a phase comparison unit that compares a phase of a receiver clock and a phase of the receiver data input to the data input unit to control the voltage levels of the first and second nodes, and a charging/discharging unit that charges or discharges electric charges that are applied to the first and second nodes.