JPS62139138U

JPS62139138U -

Info

Publication number: JPS62139138U
Application number: JP2482386U
Authority: JP
Priority date: 1986-02-21
Filing date: 1986-02-21
Publication date: 1987-09-02
Anticipated expiration: 2001-02-21
Also published as: JPH0733468Y2

Description

[Brief explanation of drawings]

第１図は本考案による周波数シンセサイザの実
施例を示す回路図、第２図は従来の周波数シンセ
サイザの回路図、第３図は従来の回路のチヤネル
指定する場合のタイミングチヤート、第４図は本
考案回路のチヤネル指定する場合のタイミングチ
ヤートである。１……基準周波数発振器、２……位相比較器、
３……電圧制御発振器、４……可変分周器、５…
…データラツチ回路、６……シフトレジスタ、７
……スイツチ、１１〜１３……抵抗、１４……コ
ンデンサ、１５……ループフイルタ、２１……ス
トローブ信号端子、２２……データ信号入力端子
、２３……クロツク信号入力端子、２４……変調
用端子、２５……ループフイルタ切替端子。 Figure 1 is a circuit diagram showing an embodiment of the frequency synthesizer according to the present invention, Figure 2 is a circuit diagram of a conventional frequency synthesizer, Figure 3 is a timing chart when specifying a channel in the conventional circuit, and Figure 4 is a diagram of the present invention. This is a timing chart when specifying the channel of the devised circuit. 1... Reference frequency oscillator, 2... Phase comparator,
3... Voltage controlled oscillator, 4... Variable frequency divider, 5...
...Data latch circuit, 6...Shift register, 7
...Switch, 11 to 13...Resistor, 14...Capacitor, 15...Loop filter, 21...Strobe signal terminal, 22...Data signal input terminal, 23...Clock signal input terminal, 24...For modulation Terminal, 25...Loop filter switching terminal.

Claims

[Claims for Utility Model Registration] (1) A reference frequency oscillator, a phase comparator for comparing the phases of the reference frequency and feedback frequency of the reference frequency oscillator, and a resistor and a capacitor, A loop filter that suppresses unnecessary components, a switch that changes the cut frequency of the loop filter, a voltage controlled oscillator that receives the phase comparator output that has passed through the loop filter, and a serial number that specifies the frequency division number. a shift register that converts data into parallel data; a data latch circuit that takes in the data in the shift register using a strobe signal; and a frequency division of the voltage controlled oscillator output based on the data latched in the data latch circuit, and A frequency synthesizer comprising a variable frequency divider that supplies the phase comparator, wherein the switch is operated by the strobe signal to raise the cutoff frequency of the loop filter for a certain period of time. . (2) The first method characterized in that the voltage controlled oscillator is a voltage controlled oscillator having a modulation signal input terminal.
Frequency synthesizer described in section.