JPS56110344A - Loop filter for pll frequency synthesizer - Google Patents

Loop filter for pll frequency synthesizer

Info

Publication number
JPS56110344A
JPS56110344A JP1312980A JP1312980A JPS56110344A JP S56110344 A JPS56110344 A JP S56110344A JP 1312980 A JP1312980 A JP 1312980A JP 1312980 A JP1312980 A JP 1312980A JP S56110344 A JPS56110344 A JP S56110344A
Authority
JP
Japan
Prior art keywords
filter
transistor
output voltage
input voltage
quickly
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP1312980A
Other languages
Japanese (ja)
Other versions
JPS5941613B2 (en
Inventor
Shigeru Kimura
Mamoru Tateishi
Michiharu Tanida
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Telegraph and Telephone Corp
Panasonic Mobile Communications Co Ltd
Original Assignee
Nippon Telegraph and Telephone Corp
Matsushita Communication Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nippon Telegraph and Telephone Corp, Matsushita Communication Industrial Co Ltd filed Critical Nippon Telegraph and Telephone Corp
Priority to JP55013129A priority Critical patent/JPS5941613B2/en
Publication of JPS56110344A publication Critical patent/JPS56110344A/en
Publication of JPS5941613B2 publication Critical patent/JPS5941613B2/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03L—AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES
    • H03L7/00—Automatic control of frequency or phase; Synchronisation
    • H03L7/06—Automatic control of frequency or phase; Synchronisation using a reference signal applied to a frequency- or phase-locked loop
    • H03L7/08—Details of the phase-locked loop
    • H03L7/10—Details of the phase-locked loop for assuring initial synchronisation or for broadening the capture range
    • H03L7/107—Details of the phase-locked loop for assuring initial synchronisation or for broadening the capture range using a variable transfer function for the loop, e.g. low pass filter having a variable bandwidth
    • H03L7/1075—Details of the phase-locked loop for assuring initial synchronisation or for broadening the capture range using a variable transfer function for the loop, e.g. low pass filter having a variable bandwidth by changing characteristics of the loop filter, e.g. changing the gain, changing the bandwidth

Landscapes

  • Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)

Abstract

PURPOSE:To reduce the frequency drawing time, by connecting each of the bases of the npn and pnp transistors to the input of a filter and each of the emitters to the output of the filter, respectively, and furthermore connecting a power source between the collectors. CONSTITUTION:The transistor 6 is turned on when the input voltage of the loop filter 8 becomes higher than the output voltage +VBE. The load capacity of the filter 8 is changed quickly by the collector current of the transistor 6. As a result, the input voltage becomes identical quickly to the output voltage. On the contrary, when the input voltage becomes lower than the output voltage -VBE, the transistor 7 is turned on. The load capacity of the filter 8 is discharged quickly by the collector current of the transistor 7. As a result, the input voltage becomes equal quickly to the output voltage. Then the input voltage becomes equal to the output voltage for the filter 8 when the PLL frequency synthesizer is locked to a certain frequency.
JP55013129A 1980-02-05 1980-02-05 Loop filter for PLL frequency synthesizer Expired JPS5941613B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP55013129A JPS5941613B2 (en) 1980-02-05 1980-02-05 Loop filter for PLL frequency synthesizer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55013129A JPS5941613B2 (en) 1980-02-05 1980-02-05 Loop filter for PLL frequency synthesizer

Publications (2)

Publication Number Publication Date
JPS56110344A true JPS56110344A (en) 1981-09-01
JPS5941613B2 JPS5941613B2 (en) 1984-10-08

Family

ID=11824538

Family Applications (1)

Application Number Title Priority Date Filing Date
JP55013129A Expired JPS5941613B2 (en) 1980-02-05 1980-02-05 Loop filter for PLL frequency synthesizer

Country Status (1)

Country Link
JP (1) JPS5941613B2 (en)

Also Published As

Publication number Publication date
JPS5941613B2 (en) 1984-10-08

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