JPH03107812U

JPH03107812U -

Info

Publication number: JPH03107812U
Application number: JP1536690U
Authority: JP
Priority date: 1990-02-19
Filing date: 1990-02-19
Publication date: 1991-11-06

Description

[Brief explanation of the drawing]

第１図は、本考案の一実施例に係るフエーズロ
ツクループ回路の構成を示す構成図、第２図は、
この実施例におけるアンロツク検出器の説明図で
あつて、第２図ａはアンロツク検出器の構成図、
第２図ｂはアンロツク検出器の動作を示すタイミ
ングチヤート図、第３図は、本考案の他の実施例
に係るフエーズロツクループ回路の構成を示す構
成図、第４図は、従来のフエーズロツクループ回
路の一例の構成を示す構成図である。１０……ＶＣＯ、１２……基準信号発生回路、
１６……位相比較器、１８，２８……ループフイ
ルタ、２０……プリエンフアシス回路、２２……
スプラツタフイルタ、２４……アナログスイツチ
、２６……アンロツク検出器。 FIG. 1 is a block diagram showing the configuration of a phase lock loop circuit according to an embodiment of the present invention, and FIG.
FIG. 2a is an explanatory diagram of the unlock detector in this embodiment, and FIG. 2a is a configuration diagram of the unlock detector;
FIG. 2b is a timing chart showing the operation of the unlock detector, FIG. 3 is a block diagram showing the configuration of a phase lock loop circuit according to another embodiment of the present invention, and FIG. 4 is a conventional phase lock loop circuit diagram. FIG. 2 is a configuration diagram showing the configuration of an example of an air lock loop circuit. 10...VCO, 12...Reference signal generation circuit,
16... Phase comparator, 18, 28... Loop filter, 20... Pre-emphasis circuit, 22...
Splatter filter, 24...analog switch, 26...unlock detector.

Claims

[Scope of claim for utility model registration] A VCO that oscillates at a frequency according to input voltage,
A reference signal generation circuit that generates a reference signal of a predetermined frequency, a phase comparator that takes in the reference signal and the output of the VCO, compares the phases, and outputs the comparison result, and outputs the output of the phase comparator to the VCO as an input voltage. A phase-locked loop circuit having a loop filter that supplies a modulation signal to the VCO and holds a loop including a VCO and a phase comparator with a predetermined time constant, and a modulation signal input section that supplies a modulation signal to the VCO and modulates the output of the VCO. , an unlock detector that detects whether the loop is in an unlock state based on the output of the VCO, and response shortening means that reduces the time constant of the loop filter when the unlock detector detects the unlock state. A phase lock loop circuit characterized by: