A detector for detecting a locked state and an out-of-lock state of a phase locked loop includes an out-of-lock detector circuit that receives a reference signal and an input signal representing a PLL oscillator signal. The out-of-lock detector detects an out-of-lock state of the PLL and generates an out-of-lock signal indicating whether an out-of-lock state is detected. The detector further includes a lock detector circuit that receives the reference signal and the input signal, detects a locked state of the PLL, and generates a lock signal indicating whether a locked state is detected. A logic circuit receives both the out-of-lock signal and the lock signal and combines both signals to obtain an output signal indicative of whether the PLL is in a locked state or an out-of-lock state.