WO2001008388A1 - Reduced power line driver - Google Patents
Reduced power line driver Download PDFInfo
- Publication number
- WO2001008388A1 WO2001008388A1 PCT/US2000/020265 US0020265W WO0108388A1 WO 2001008388 A1 WO2001008388 A1 WO 2001008388A1 US 0020265 W US0020265 W US 0020265W WO 0108388 A1 WO0108388 A1 WO 0108388A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- circuit
- line
- transformer
- cunent
- voltage
- Prior art date
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
- H04M19/003—Arrangements for compensation of the DC flux in line transformers
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Definitions
- This invention relates to a method and system for reducing power consumption in a line driver.
- a loop is a twisted-pair copper telephone line coupling a user or subscriber telephone to a central office (CO).
- CO central office
- Traditional data communication equipment uses the voice band of the subscriber loop.
- Such equipment includes voice band modems, which operate at up to 56 kbps using compression techniques.
- ISDN Integrated Services Digital Network
- ISDN Integrated Services Digital Network
- traditional voice bands equipment is limited by the maximum data rate of the existing switching networks and PCM (Pulse Code Modulation) data highways.
- ADSL is intended to co-exist with traditional voice services by using different frequency spectra on the loop.
- multiple different transmission schemes may be employed in different frequency bands on the same loop, and that these transmission schemes may include traditional analog voice services as well as current and new forms of xDSL.
- POTS plain old telephone services
- the ADSL uses the frequency spectrum between 30 kHz and 1.1 MHz for data over the telephone line. This is shown schematically in Figure la.
- ADSL also partitions its frequency spectrum with upstream (subscriber to CO) transmission in a lower frequency band, typically 30 kHz to 138 kHz, and with downstream transmission in a higher frequency band, typically 138 kHz to 550 kHz or 1.1 MHz.
- ADSL uses a discrete multi-tone (DMT) multi-carrier technique that divides the available bandwidth into approximately 4 kHz sub-channels.
- DMT discrete multi-tone
- the line driver is a component that consumes a significant amount of power.
- the line driver includes an amplifier for receiving an analog signal from a preceding circuit, such as a digital to analog (DA) converter on the xDSL line card, to drive this signal through a source resistance and a line transformer onto a twisted pair telephone line or loop.
- DA digital to analog
- the xDSL line drivers commonly in use include a source or feed resistance equal to the reference impedance of the loop, usually 100 ohms implemented as a series resistance. Typical line drivers use two amplifiers working differentially.
- a telephone line feed circuit for use with a telecommunication line includes a transformer having a primary winding and a secondary winding wound with low resistance conductors, the primary for direct connection to a tip terminal and a ring terminal, and a driver circuit having an output connected to a secondary winding of the transformer for driving the transformer secondary winding directly with substantially no resistance therebetween while maintaining an impedance match between the telecommunications line and the telephone line feed circuit, to thereby reduce power consumption of the driver circuit.
- the present invention seeks to provide a line interface circuit that allows the significant reduction of driver power, namely up to about 50%.
- the line feed circuit includes an active impedance synthesis circuit for generating the line impedance for xDSL signals. In another embodiment the line feed circuit includes an active impedance synthesis circuit for generating the line impedance for POTS signals.
- the line feed circuit is coupled to an integrated POTS/xDSL line card.
- the line feed circuit includes an active impedance synthesis circuit for generating line impedances for both xDSL and POTS signals.
- Figure 1 is a schematic diagram of a line feed circuit according to the prior art.
- Figure 2 is a schematic diagram of a line feed circuit according to an embodiment of the invention.
- Figure 3 is a schematic diagram of a line feed circuit with a current sense feedback.
- Figure 4 is a schematic diagram of a line feed circuit with a current sense feedback according to a further embodiment of the invention.
- Figure 5 is a schematic diagram of a line feed circuit with a current sense feedback using a transformer.
- Figure 6 is a schematic diagram of a line feed circuit with a current sense feedback using a transformer according to a further embodiment of the invention.
- Figure 7 is a schematic diagram of a line feed circuit with a voltage sense feedback.
- the line feed circuit 10 includes driver stage 12, feed resistors 18 and a line transformer 19.
- the driver stage normally comprises two driver amplifier circuits 14 and 16 (normally fixed-gain amplifiers) for supplying a subscriber line comprising tip T and ring R lines, via respective series feed resistors R F 18.
- a load resistance R L normally terminates the line.
- the line is normally terminated by a load resistance R L of typically 100 ohms, thus the series feed resistors R F are chosen to equal the reference impedance of the loop, i.e. 50 ohms each.
- Other values of the feed resistors are chosen for different signals such as POTS signals.
- the drive amplifiers 14 and 16 are each powered by (+)V supp i y voltage rails referenced to ground.
- the drive amplifiers may be powered by (")V SUpp i y /2 and (+)V supp ⁇ y /2 voltage rails.
- V h total voltage headroom required on side of the voltage rail for allowing proper biasing of the drive amplifiers, typically 3V/2;
- R s total source resistance;
- the total differential driver power consumption for xDSL signals can be defined in terms of the driver supply voltage and the required cunent to be driven onto the line, as follows:
- P drlve 2*(Vh + ((R s +R tr )/(n*R tr )*V t ,/2 * ⁇ )*(V2/ ⁇ *nV tr /R L + 2*I b ) (1)
- the supply voltage Vsupply is a function of the total resistance, the cunent and the crest factor requirement. Power consumption can be calculated for the circuit in Figure 1 assuming
- a mechanism for reducing the nominal DSL driver power consumption (ideally by 50%) by driving the DSL signal directly onto the line and not through a source resistance.
- the source resistance is actively generated through feedback.
- a telephone line feed circuit 20 for use with a telecommunication line, comprises a transformer 29 having a primary and secondary winding wound with low resistance conductors; the primary for direct connection to the tip T terminal and a ring terminal R of a telecommunication line, a driver circuit 22 having an output 23 connected to the secondary winding of the transformer for driving the transformer secondary winding directly with substantially no resistance therebetween, a sensing circuit 27 for producing a feedback signal which is combined in a summing circuit 21 with the signal from the preceding xDSL/POTS circuit (not shown) to the driver circuit 22, while maintaining an impedance match between the telecommunications line and the telephone line feed circuit, to thereby reduce power consumption of the driver circuit 22.
- the feedback signal from the sensing circuit 27 represents either the loop current I ⁇ flowing differentially in the tip and ring lines or the voltage Vtr between the tip and ring lines.
- the drive stage 22 includes two drive amplifiers operating differentially.
- a line feed circuit according to a first embodiment of the invention is shown by numeral 30.
- the following additional symbols are used:
- K gain of the sense amplifier.
- the line feed circuit 30 comprises two voltage sources 32 and 34 , coupled via respective cunent sense resistors 36 and 38 to the secondary winding of a line transformer 40.
- the cunent I sense through the each sense resistor R sen se generates a voltage V senS e, which is sensed and applied to the differential inputs of a sense amplifier 42.
- the output of the sense amplifier is amplified and fed back as an input to the voltage sources 32 and 34.
- the gain K of the sense amplifier 42 is chosen so that the voltage feedback to drivers 32 and 34 causes the drivers to drive a voltage sufficient to maintain the output impedance at Z out .
- V 0 ut (Zout - 2*Rfeed) * Ifeed
- the gain K of the feedback amplifier is thus chosen to be 90. Because a separate drive is used to drive the tip and ring lines, the gain of these voltage source drivers 32 and 34 is chosen to be (+)0.5 and (-)0.5 respectively.
- These amplifiers may be easily implemented by one of many known circuits as is well known in the art and will not be discussed further. Furthermore the summing circuit in the illustrated embodiment is implemented using a simple series connected resistors as shown. However, other summing circuits known in the art may equally well be used.
- FIG. 4 A variation of the circuit of Figure 3 is shown in Figure 4.
- the cunent sensing is on the tip and ring side (primary) of the transformer.
- the sense resistors are indicated as 36' and 38' respectively.
- the gain of the feedback amplifier K is 90, based on the computation as for the circuit of Figure 3.
- a third embodiment of the invention is indicated generally by numeral 50.
- using a sense transformer 52 performs the cunent sense.
- An advantage of this configuration is that there is no power loss by using a sense resistor.
- gain K of the feedback amplifier 42 is chosen to be 100.
- Cunent sense transformers are well known in the art and will not be discussed further.
- FIG. 6 A variation of the circuit of Figure 5 is shown in Figure 6.
- the cunent sensing is performed on the tip and ring side of the line transformer 40.
- a fifth embodiment of the active source resistance generation circuit 70 for the driver stage comprises two cunent sources 72 and 74, coupled directly to the secondary winding of a line transformer 40.
- a voltage sense amplifier 76 is coupled to receive the voltage across the transformer primary Vtr i.e. at the line side, which is amplified by the gain K' of the amplifier 76 and fed back as an input to the cunent sources 72 and 74.
- the gain K' of the sense amplifier 76 is chosen so that the cunent feed back to drivers 72 and 74 causes the drivers to drive a cunent into the secondary of the transformer 40 sufficient to match the output impedance to Zout.
- the gain K' of the amplifier 76 is 0.01
- turns ratio of the line transformer used for illustration purposes is 1 :1.
- Other turns ratios may equally well be used, such as 1 :2, 2:1, etc.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Signal Processing (AREA)
- Interface Circuits In Exchanges (AREA)
- Devices For Supply Of Signal Current (AREA)
- Dc Digital Transmission (AREA)
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU64934/00A AU6493400A (en) | 1999-07-26 | 2000-07-25 | Reduced power line driver |
JP2001512771A JP2003505982A (en) | 1999-07-26 | 2000-07-25 | Low power line driver |
CA002379519A CA2379519A1 (en) | 1999-07-26 | 2000-07-25 | Reduced power line driver |
EP00952189A EP1206872A4 (en) | 1999-07-26 | 2000-07-25 | Reduced power line driver |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA2,278,909 | 1999-07-26 | ||
CA002278909A CA2278909A1 (en) | 1999-07-26 | 1999-07-26 | Reduced power line driver |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2001008388A1 true WO2001008388A1 (en) | 2001-02-01 |
Family
ID=4163837
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2000/020265 WO2001008388A1 (en) | 1999-07-26 | 2000-07-25 | Reduced power line driver |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP1206872A4 (en) |
JP (1) | JP2003505982A (en) |
AU (1) | AU6493400A (en) |
CA (1) | CA2278909A1 (en) |
WO (1) | WO2001008388A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100454956C (en) * | 2003-12-19 | 2009-01-21 | 上海贝尔阿尔卡特股份有限公司 | A circuit for reducing ring current source power consumption |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5515433A (en) * | 1994-08-30 | 1996-05-07 | Reltec Corporation | Resistance forward telephone line feed circuit |
US6067316A (en) * | 1997-11-19 | 2000-05-23 | Globespan, Inc. | Circuit for combined xDSL and other services |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AU8613998A (en) * | 1997-06-17 | 1999-01-04 | Paradyne Corporation | A method and apparatus for controlling the input impedance of an analog front end circuit of a data communications equipment (dce) device |
-
1999
- 1999-07-26 CA CA002278909A patent/CA2278909A1/en not_active Abandoned
-
2000
- 2000-07-25 AU AU64934/00A patent/AU6493400A/en not_active Abandoned
- 2000-07-25 JP JP2001512771A patent/JP2003505982A/en active Pending
- 2000-07-25 WO PCT/US2000/020265 patent/WO2001008388A1/en not_active Application Discontinuation
- 2000-07-25 EP EP00952189A patent/EP1206872A4/en not_active Withdrawn
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5515433A (en) * | 1994-08-30 | 1996-05-07 | Reltec Corporation | Resistance forward telephone line feed circuit |
US6067316A (en) * | 1997-11-19 | 2000-05-23 | Globespan, Inc. | Circuit for combined xDSL and other services |
Non-Patent Citations (1)
Title |
---|
See also references of EP1206872A4 * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100454956C (en) * | 2003-12-19 | 2009-01-21 | 上海贝尔阿尔卡特股份有限公司 | A circuit for reducing ring current source power consumption |
Also Published As
Publication number | Publication date |
---|---|
JP2003505982A (en) | 2003-02-12 |
EP1206872A4 (en) | 2004-03-03 |
CA2278909A1 (en) | 2001-01-26 |
EP1206872A1 (en) | 2002-05-22 |
AU6493400A (en) | 2001-02-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6295343B1 (en) | Method and apparatus for combining voice line card and xDSL line card functions | |
US6674845B2 (en) | Method and apparatus for connecting broadband voice and data signals to telephone systems | |
US5898342A (en) | Power amplifier arrangement and method for data signal interface | |
US5329585A (en) | Subscriber line interface circuit for controlling AC and DC output impedance | |
EP1843610B1 (en) | A communication apparatus and a method for saving static power consumption of the communication apparatus | |
US20130003940A1 (en) | Xdsl multistandard driver circuit | |
US6529563B1 (en) | Method and apparatus for providing a self-sustaining precision voltage and current feedback biasing loop | |
US6323686B1 (en) | Crest factor compensated driver | |
US6741700B1 (en) | Low insertion loss current sense circuit | |
US6531902B1 (en) | Line driver operative from a single supply and method for supplying voltages to a load | |
EP1206872A1 (en) | Reduced power line driver | |
US6369650B1 (en) | Impedance synthesis and DC biasing method and architecture for DSL/cable line drivers | |
CA2379519A1 (en) | Reduced power line driver | |
US20100080381A1 (en) | Method and Apparatus for Supplying DC Feed to a Subscriber Line | |
CA2274171A1 (en) | Loop driver for pots, xdsl, or integrated pots/xdsl interface | |
CA2390542A1 (en) | A low insertion loss current sense circuit | |
WO2002028111A2 (en) | Improved technique for remote power feeding of telephone subscribers | |
US6678377B1 (en) | Monolithically integrated telephone circuit for driving wide-band telephone lines for data transmission | |
CA2375153A1 (en) | Loop driver for pots, xdsl, or integrated pots/xdsl interface | |
Huijsing | PART III: LINE AND BUS DRIVERS | |
WO2003043293A1 (en) | System and method for reducing power dissipation for dsl circuits | |
CA2321509A1 (en) | Feed arrangement for a subscriber loop with multi-level current regulation capability |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CR CU CZ DE DK DM DZ EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG US UZ VN YU ZA ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ 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) | ||
WWE | Wipo information: entry into national phase |
Ref document number: 2379519 Country of ref document: CA |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2000952189 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 64934/00 Country of ref document: AU |
|
WWP | Wipo information: published in national office |
Ref document number: 2000952189 Country of ref document: EP |
|
REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 2000952189 Country of ref document: EP |