SE8804461D0 - Clock holdover circuit - Google Patents

Clock holdover circuit

Info

Publication number
SE8804461D0
SE8804461D0 SE8804461A SE8804461A SE8804461D0 SE 8804461 D0 SE8804461 D0 SE 8804461D0 SE 8804461 A SE8804461 A SE 8804461A SE 8804461 A SE8804461 A SE 8804461A SE 8804461 D0 SE8804461 D0 SE 8804461D0
Authority
SE
Sweden
Prior art keywords
clock signal
frequency
loss
reference clock
local
Prior art date
Application number
SE8804461A
Other languages
English (en)
Other versions
SE8804461L (sv
SE501385C2 (sv
Inventor
T Warren
Original Assignee
Silicon General Inc
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 Silicon General Inc filed Critical Silicon General Inc
Publication of SE8804461D0 publication Critical patent/SE8804461D0/sv
Publication of SE8804461L publication Critical patent/SE8804461L/sv
Publication of SE501385C2 publication Critical patent/SE501385C2/sv

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
    • H03L7/14—Details of the phase-locked loop for assuring constant frequency when supply or correction voltages fail or are interrupted
    • H03L7/143—Details of the phase-locked loop for assuring constant frequency when supply or correction voltages fail or are interrupted by switching the reference signal of the phase-locked loop
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L7/00—Arrangements for synchronising receiver with transmitter
    • H04L7/0079—Receiver details
    • H04L7/0083—Receiver details taking measures against momentary loss of synchronisation, e.g. inhibiting the synchronisation, using idle words or using redundant clocks
    • 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
    • H03L7/14—Details of the phase-locked loop for assuring constant frequency when supply or correction voltages fail or are interrupted
    • H03L7/143—Details of the phase-locked loop for assuring constant frequency when supply or correction voltages fail or are interrupted by switching the reference signal of the phase-locked loop
    • H03L7/145—Details of the phase-locked loop for assuring constant frequency when supply or correction voltages fail or are interrupted by switching the reference signal of the phase-locked loop the switched reference signal being derived from the controlled oscillator output signal

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
  • Electric Clocks (AREA)
  • Synchronisation In Digital Transmission Systems (AREA)
SE8804461A 1987-12-10 1988-12-09 Krets för bibehållande av en klocksignal SE501385C2 (sv)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US07/131,141 US4849993A (en) 1987-12-10 1987-12-10 Clock holdover circuit

Publications (3)

Publication Number Publication Date
SE8804461D0 true SE8804461D0 (sv) 1988-12-09
SE8804461L SE8804461L (sv) 1989-06-11
SE501385C2 SE501385C2 (sv) 1995-01-30

Family

ID=22448075

Family Applications (1)

Application Number Title Priority Date Filing Date
SE8804461A SE501385C2 (sv) 1987-12-10 1988-12-09 Krets för bibehållande av en klocksignal

Country Status (6)

Country Link
US (1) US4849993A (sv)
JP (1) JPH022722A (sv)
DE (1) DE3841512A1 (sv)
FR (1) FR2626690B1 (sv)
GB (1) GB2213664B (sv)
SE (1) SE501385C2 (sv)

Families Citing this family (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4980899A (en) * 1988-06-21 1990-12-25 Siemens Ag Method and apparatus for synchronization of a clock signal generator particularly useful in a digital telecommunications exchange
DE3833940A1 (de) * 1988-09-22 1990-04-05 Siemens Ag Verfahren zur neusynchronisation einer vermittlungsstelle in einem fernmeldenetz
US4964117A (en) * 1988-10-04 1990-10-16 Vtc Incorporated Timing synchronizing circuit for baseband data signals
US5208831A (en) * 1989-10-26 1993-05-04 Kabushiki Kaisha Toshiba Network interface system
FI85084C (sv) * 1990-08-15 1992-02-25 Computec Oy Förfarande och anordning för mottagning av paketformigt data
FI91821C (sv) * 1991-02-22 1994-08-10 Nokia Mobile Phones Ltd Koppling för automatisk frekvensreglering i en radiotelefon
CA2091962A1 (en) * 1992-03-31 1993-10-01 Mark L. Witsaman Clock synchronization system
US5365569A (en) * 1992-08-17 1994-11-15 Glenayre Electronics, Ltd. Digital simulcast transmission system
US5369682A (en) * 1992-08-17 1994-11-29 Glenayre Electronics, Inc. Digital simulcast transmission system
JPH084235B2 (ja) * 1993-03-31 1996-01-17 日本電気株式会社 周波数制御装置
US5349310A (en) * 1993-06-09 1994-09-20 Alcatel Network Systems, Inc. Digitally controlled fractional frequency synthesizer
AU6339594A (en) * 1993-06-09 1994-12-15 Alcatel N.V. Synchronized clock
US5481258A (en) * 1993-08-11 1996-01-02 Glenayre Electronics, Inc. Method and apparatus for coordinating clocks in a simulcast network
US5410368A (en) * 1993-12-29 1995-04-25 Zenith Electronics Corp. Carrier acquisition by applying substitute pilot to a synchronous demodulator during a start up interval
GB2293062B (en) * 1994-09-09 1996-12-04 Toshiba Kk Master-slave multiplex communication system and PLL circuit applied to the system
US5717402A (en) * 1994-12-09 1998-02-10 Chu; Peter GPS reference clock generator
JP3523718B2 (ja) * 1995-02-06 2004-04-26 株式会社ルネサステクノロジ 半導体装置
US5982831A (en) * 1996-02-21 1999-11-09 Hewlett-Packard Company Feed forward method and apparatus for generating a clock signal
US6243372B1 (en) * 1996-11-14 2001-06-05 Omnipoint Corporation Methods and apparatus for synchronization in a wireless network
WO1998045950A1 (de) * 1997-04-07 1998-10-15 Siemens Aktiengesellschaft Digitale afc-einstellung durch reziproke dds
US5963098A (en) * 1997-08-22 1999-10-05 Technology Service Corporation FM canceler loop to reduce shock and vibration effects in crystal oscillators
US7881413B2 (en) * 2001-03-02 2011-02-01 Adc Telecommunications, Inc. Digital PLL with conditional holdover
US6725157B1 (en) * 2002-06-10 2004-04-20 Trimble Navigation Limited Indoor GPS clock
JP4624796B2 (ja) * 2002-11-21 2011-02-02 ソニー エリクソン モバイル コミュニケーションズ， エービー 発振周波数の制御
US7643602B2 (en) * 2005-09-30 2010-01-05 Freescale Semiconductor, Inc. Method and system for estimating frequency offsets
US8120430B1 (en) 2009-01-15 2012-02-21 Xilinx, Inc. Stable VCO operation in absence of clock signal
WO2011086976A1 (ja) * 2010-01-13 2011-07-21 古野電気株式会社 基準周波数発生装置
US8634510B2 (en) * 2011-01-12 2014-01-21 Qualcomm Incorporated Full digital bang bang frequency detector with no data pattern dependency
CN102427366B (zh) * 2011-12-15 2013-09-18 上海唯星通信技术有限公司 精确合成北斗终端模块多个频率源的装置和方法
EP2976851B1 (en) 2013-03-21 2019-11-13 Telefonaktiebolaget LM Ericsson (publ) Method and apparatus for implementing clock holdover
US9648414B1 (en) * 2014-01-31 2017-05-09 Cirrus Logic, Inc. Systems and methods for controlling an audio signal path using redundant uninterruptable clock
US9362926B2 (en) 2014-02-19 2016-06-07 Arbiter Systems, Incorporated High-reliability holdover method and topologies
US11487871B2 (en) * 2015-01-31 2022-11-01 San Diego Gas & Electric Company Methods and systems for detecting and defending against invalid time signals

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1194924B (de) * 1961-06-29 1965-06-16 Csf Anordnung zur Regelung der Frequenz eines UEberlagerungsoszillators
CH1229067A4 (sv) * 1967-09-01 1970-05-29
US4069462A (en) * 1976-12-13 1978-01-17 Data General Corporation Phase-locked loops
US4034310A (en) * 1977-01-05 1977-07-05 Coe Thomas F Phase-locked loop oscillator
US4310805A (en) * 1979-12-13 1982-01-12 General Electric Company Phase-locked loop stabilized by a crystal oscillator
NL8202685A (nl) * 1982-07-05 1984-02-01 Philips Nv Kloksignaalregenerator met hoge stabiliteit.
FR2546691B1 (fr) * 1983-05-27 1985-07-05 Cit Alcatel Base de temps asservie
US4598257A (en) * 1983-05-31 1986-07-01 Siemens Corporate Research & Support, Inc. Clock pulse signal generator system
US4498059A (en) * 1983-06-23 1985-02-05 Gte Automatic Electric Incorporated Circuit to minimize local clock frequency disturbances when phase locking to a reference clock circuit
US4667328A (en) * 1985-04-29 1987-05-19 Mieczyslaw Mirowski Clocking circuit with back-up clock source
US4835481A (en) * 1986-09-30 1989-05-30 Siemens Aktiengesellschaft Circuit arrangement for generating a clock signal which is synchronous in respect of frequency to a reference frequency

Also Published As

Publication number Publication date
JPH022722A (ja) 1990-01-08
SE8804461L (sv) 1989-06-11
US4849993A (en) 1989-07-18
GB8828673D0 (en) 1989-01-11
DE3841512C2 (sv) 1990-10-04
GB2213664B (en) 1992-08-19
FR2626690B1 (fr) 1991-01-11
DE3841512A1 (de) 1989-06-29
FR2626690A1 (fr) 1989-08-04
GB2213664A (en) 1989-08-16
SE501385C2 (sv) 1995-01-30

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Legal Events

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