PHASE LOCK DETECTOR OF PHASE LOCKED LOOP

摘要

PURPOSE: A phase lock detector is provided to avoid the use of passive devices and reduce the production cost by changing the state of a phase lock signal when maintaining the lock state more than the predetermined number of times. CONSTITUTION: A window signal generator(211) generates a window signal having a pulse width corresponding to a phase difference in response to an input signal. A delay circuit(212) delays an output signal frequency-divided by a frequency divider. A first detector(220) detects whether the frequency-divided delay signal exists in the pulse width of the window signal and generates a first detection signal and a second detection signal compensatory to the first detection signal. A toggle unit(270) generates a toggle signal based on a basic clock of the input signal.