| 摘要 |
PROBLEM TO BE SOLVED: To obtain the phase locked loop circuit that requires no adjustment, includes no inductive element and locks a phase at a high speed and to obtain the electronic device provided with the circuit. SOLUTION: A phase lock detector 11 detects the presence of an intermediate frequency signal, an output of a low frequency oscillator 10 is given to a 2nd control terminal 18 of a VCO 3 when no intermediate frequency signal is received to trace the frequency from an upper limit to a lower limit of an oscillated frequency from the VCO within its variable range. The moment the intermediate frequency signal is received in this state and a phase of a phase locked loop 26 is locked, a changeover means 20 feeds back negatively an output from a comparator means 19 to the 2nd control terminal 18 of the VCO 3 and the phase of the output of the VCO 3 is locked at a center frequency equal to a video carrier depending on a reference voltage 9. |
