WO1999029098A3 - Subscriber line interface circuit - Google Patents

Subscriber line interface circuit Download PDF

Info

Publication number
WO1999029098A3
WO1999029098A3 PCT/FI1998/000898 FI9800898W WO9929098A3 WO 1999029098 A3 WO1999029098 A3 WO 1999029098A3 FI 9800898 W FI9800898 W FI 9800898W WO 9929098 A3 WO9929098 A3 WO 9929098A3
Authority
WO
WIPO (PCT)
Prior art keywords
voltage
amplifier
subscriber line
polarity
output
Prior art date
Application number
PCT/FI1998/000898
Other languages
French (fr)
Other versions
WO1999029098A2 (en
Inventor
Caj Nordstroem
Harri Hurme
Original Assignee
Nokia Telecommunications Oy
Caj Nordstroem
Harri Hurme
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 Nokia Telecommunications Oy, Caj Nordstroem, Harri Hurme filed Critical Nokia Telecommunications Oy
Priority to AU12376/99A priority Critical patent/AU1237699A/en
Priority to EP98955604A priority patent/EP1025690A2/en
Publication of WO1999029098A2 publication Critical patent/WO1999029098A2/en
Publication of WO1999029098A3 publication Critical patent/WO1999029098A3/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M19/00—Current supply arrangements for telephone systems
    • H04M19/001—Current supply source at the exchanger providing current to substations
    • H04M19/005—Feeding arrangements without the use of line transformers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M19/00—Current supply arrangements for telephone systems
    • H04M19/02—Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone
    • H04M19/023—Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone by reversing the polarity of the current at the exchange

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
  • Interface Circuits In Exchanges (AREA)

Abstract

An output stage of a subscriber line interface circuit comprises two amplifiers, a first (111) one of which is configured to operate as an inverting amplifier (negative amplification) and a second (110) one as a non-inverting amplifier (positive amplification). Each amplifier has an output connected to a respective wire (a, b) in a subscriber line. A common reference voltage (Vref) and a common control voltage (Vc) are supplied to each amplifier (110, 111). The reference voltage (Vref) is used for setting the average voltage of the subscriber line. The control voltage (Vc) level determines the offset of the amplifier output voltages (Vb, Va) from the average voltage. The difference between the amplifier output voltages is the subscriber line supply voltage. A polarity reversal circuit (128) supplies the control voltage (Vc) to the amplifiers (110, 111) at a first polarity or at a second, reversed polarity, depending on a state of a polarity control signal supplied by a telephone exchange. This offers a simple way of providing polarity reversal which is used in the telephone system for signalling transferred from an exchange to a subscriber terminal over a subscriber line. When the polarity of the control voltage is changed, the output voltage of the first amplifier (110) changes from operating voltage to ground and the output voltage of the second amplifier (111) from ground to operating voltage, or vice versa.
PCT/FI1998/000898 1997-11-18 1998-11-17 Subscriber line interface circuit WO1999029098A2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU12376/99A AU1237699A (en) 1997-11-18 1998-11-17 Subscriber line interface circuit
EP98955604A EP1025690A2 (en) 1997-11-18 1998-11-17 Subscriber line interface circuit

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI974270A FI104933B (en) 1997-11-18 1997-11-18 SLIC
FI974270 1997-11-18

Publications (2)

Publication Number Publication Date
WO1999029098A2 WO1999029098A2 (en) 1999-06-10
WO1999029098A3 true WO1999029098A3 (en) 1999-09-02

Family

ID=8549972

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI1998/000898 WO1999029098A2 (en) 1997-11-18 1998-11-17 Subscriber line interface circuit

Country Status (4)

Country Link
EP (1) EP1025690A2 (en)
AU (1) AU1237699A (en)
FI (1) FI104933B (en)
WO (1) WO1999029098A2 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10124965A1 (en) * 2001-05-21 2002-12-12 Infineon Technologies Ag Method for switching a reference voltage potential for surge protective devices

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4317963A (en) * 1980-09-22 1982-03-02 International Telephone And Telegraph Corporation Subscriber line interface circuit utilizing impedance synthesizer and shared voltage source for loop current regulation control
US4431868A (en) * 1981-07-09 1984-02-14 International Telephone And Telegraph Corporation Solid state telephone line interface circuit with ringing capability
GB2193063A (en) * 1986-07-08 1988-01-27 Toshiba Kk Line circuits
US4853959A (en) * 1986-06-27 1989-08-01 Telefonaktiebolaget L M Ericsson Method and apparatus for feeding power to a telephone line such that for restricted battery voltage there is enabled the transmission of an undistorted speech signal
US4872199A (en) * 1984-12-27 1989-10-03 Fujitsu Limited Battery-feed circuit for exchange
WO1996015617A1 (en) * 1994-11-10 1996-05-23 Telefonaktiebolaget Lm Ericsson (Publ) Supply voltage switching apparatus

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4317963A (en) * 1980-09-22 1982-03-02 International Telephone And Telegraph Corporation Subscriber line interface circuit utilizing impedance synthesizer and shared voltage source for loop current regulation control
US4431868A (en) * 1981-07-09 1984-02-14 International Telephone And Telegraph Corporation Solid state telephone line interface circuit with ringing capability
US4872199A (en) * 1984-12-27 1989-10-03 Fujitsu Limited Battery-feed circuit for exchange
US4853959A (en) * 1986-06-27 1989-08-01 Telefonaktiebolaget L M Ericsson Method and apparatus for feeding power to a telephone line such that for restricted battery voltage there is enabled the transmission of an undistorted speech signal
GB2193063A (en) * 1986-07-08 1988-01-27 Toshiba Kk Line circuits
WO1996015617A1 (en) * 1994-11-10 1996-05-23 Telefonaktiebolaget Lm Ericsson (Publ) Supply voltage switching apparatus

Also Published As

Publication number Publication date
FI104933B (en) 2000-04-28
WO1999029098A2 (en) 1999-06-10
FI974270A (en) 1999-05-19
FI974270A0 (en) 1997-11-18
AU1237699A (en) 1999-06-16
EP1025690A2 (en) 2000-08-09

Similar Documents

Publication Publication Date Title
GB2102249A (en) Telephone line circuit
US3894187A (en) Circuit for comparing at least two input signals to generate control signals
JPH0636539B2 (en) DC control circuit for telephone interface circuit
WO1999029098A3 (en) Subscriber line interface circuit
WO1999027703A3 (en) Subscriber line interface circuit
EP0846367B1 (en) Bridge amplifier with feedback over the load
US4723280A (en) Constant current line circuit
GB2120498A (en) Regulator circuit
JPH0462218B2 (en)
US4800586A (en) Compensation circuit for use with an integrating amplifier
EP1369990A1 (en) Canceling feedback resistor loading effect in a shunt-shunt feedback circuit
JP4254485B2 (en) Current detection circuit
US4674117A (en) Subscriber line circuit having an improved offhook supervision circuit
US5045809A (en) Automatic gain control (AGC) circuit for a trunk interface in a private branch exchange (PBX)
US5636274A (en) Switch controller and method
US5289537A (en) On-hook transmission circuit in cable line
JP3452833B2 (en) Comparator circuit
US6766152B2 (en) Signal treating circuit with a class A/B output stage connectable to a source of multiple supply voltages
KR100258757B1 (en) Gain control circuit
KR100563014B1 (en) Line Driver with Adaptive Output Impedance
KR960013042B1 (en) Amp gain control circuit using impedance control
US6950512B1 (en) Circuit arrangement for forming the termination of an analogous subscriber line
JPH0342825B2 (en)
KR20010013386A (en) A method in a subscriber line interface circuit as well as a subscriber line interface circuit
WO1999027704A3 (en) Subscriber line interface circuit

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): AL AM AT AT AU AZ BA BB BG BR BY CA CH CN CU CZ CZ DE DE DK DK EE EE ES FI FI GB GD GE GH GM HR HU ID IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SK SL TJ TM TR TT UA UG US UZ VN YU ZW

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): GH GM KE LS MW SD SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
AK Designated states

Kind code of ref document: A3

Designated state(s): AL AM AT AT AU AZ BA BB BG BR BY CA CH CN CU CZ CZ DE DE DK DK EE EE ES FI FI GB GD GE GH GM HR HU ID IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SK SL TJ TM TR TT UA UG US UZ VN YU ZW

AL Designated countries for regional patents

Kind code of ref document: A3

Designated state(s): GH GM KE LS MW SD SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

WWE Wipo information: entry into national phase

Ref document number: 1998955604

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: KR

WWP Wipo information: published in national office

Ref document number: 1998955604

Country of ref document: EP

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

NENP Non-entry into the national phase

Ref country code: CA

WWW Wipo information: withdrawn in national office

Ref document number: 1998955604

Country of ref document: EP