CN1250998A - Subscriber matched circuit for electronic exchanger - Google Patents
Subscriber matched circuit for electronic exchanger Download PDFInfo
- Publication number
- CN1250998A CN1250998A CN99117992A CN99117992A CN1250998A CN 1250998 A CN1250998 A CN 1250998A CN 99117992 A CN99117992 A CN 99117992A CN 99117992 A CN99117992 A CN 99117992A CN 1250998 A CN1250998 A CN 1250998A
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- China
- Prior art keywords
- transistor
- current
- resistance
- match circuit
- line
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q1/00—Details of selecting apparatus or arrangements
- H04Q1/18—Electrical details
- H04Q1/30—Signalling arrangements; Manipulation of signalling currents
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
- H04Q2213/1309—Apparatus individually associated with a subscriber line, line circuits
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Interface Circuits In Exchanges (AREA)
- Amplifiers (AREA)
- Devices For Supply Of Signal Current (AREA)
Abstract
A hybrid subscriber matching circuit for an electronic exchange which matches transmitted/received data so as to permit call communications between the exchange and subscribers. The subscriber matching circuit is constructed by individual parts without using a transformer or SLIC, and thus can simplify the peripheral parts thereof as well as strongly resist external impact.
Description
The present invention relates to user's match circuit of electron exchanger.Particularly, the present invention relates to be used to mate the data that send/receive so that allow between switch and user, to carry out user's match circuit call communication, that be used for electron exchanger.
Usually, in electron exchanger, be used for needing line current supply, User Status supervision, call signal to supply with (bell signal supply) and detection and 2-line/functions such as 4-line conversion with user's match circuit of user's coupling.The line current functions of physical supply is used for electric current being provided and being used for coming by the variation that detects supplying electric current the on-hook/off hook state of monitoring telephone for subscriber phone work.This line current functions of physical supply that limits maximum circuit function of current that has can be used to prevent unnecessary power consumption owing to providing line current to cause to the short distance user excessively.2-line/4-line translation function is used for becoming 2-line signal from telephone exchange or by the 4-line conversion of signals that transmission line sends, and simultaneously the 2-line conversion of signals that sends from subsets is become 4-line signal.
User's match circuit of such analog type can adopt transformer.Yet because the magnetic saturation that its large scale and line current cause, it is not suitable for the high integration of today and the trend of miniaturization.
In order to be suitable for the trend of high integration and miniaturization, user's match circuit is integrated into SLIC integrated circuit (IC).In the korean patent application No.1994-40809 that submits to by applicant of the present invention, disclosed the user's match circuit that uses SLIC IC.Yet, according to the user's match circuit that in korean patent application No.1994-40809, is disclosed, all circuit elements are integrated on the chip, so it is compared with the circuit that adopts transformer, and it is relatively fragile impacting (for example lightning discharge) for external pulse.As a result, in order to carry out user's matching feature, its need protection device and many peripheral components thereof has increased the possibility that encounters difficulties thus when work.
The objective of the invention is to solve the problem that relates in correlation technique, and a kind of hybrid subscriber match circuit that is used for electron exchanger is provided, it can simplify its peripheral components, and the effectively outside pulse shock of opposing.
In order to reach above purpose, a kind of user's match circuit that is used for full-electronic switching system is provided, it comprises: transistor Q1 and Q2 are used for providing line current to the user by plug tip terminal and plug ring terminal; Have Darlington (Darlington) structure and the transistor Q3 and the Q4 that are connected respectively to transistor Q1 and Q2, be used to limit maximum current; Be connected respectively to the current surveillance resistance R 1 and the R2 of the emitter of transistor Q1 and Q2, be used to realize that the current feedback operation is to limit maximum current and to be used for detecting the line current that flows through telephone wire with voltage form; Be connected the resistance R 3 between the collector electrode of the collector electrode of transistor Q1 and transistor Q3, be used to prevent that transistor Q1 is saturated; Be connected the resistance R 4 between the collector electrode of the collector electrode of transistor Q2 and transistor Q4, be used to prevent that transistor Q2 is saturated; Three base resistance R5, R6, and R7 are used for determining the threshold value of maximum current and making transistor Q1 and Q2 always be in the service area; Capacitor C 5 and C6 are used for an AC audio signal that the receives DC line current that is added to; Composite impedance ZL1 and ZL2 are used for mating with line characteristic impedance; Resistance R 11 is used for the line current that flows through resistance R 1 is converted to the input current that is used to detect off hook state; Operational amplifier A MP3 is used for the signal of paraphase-amplification by resistance R 11 inputs; And transistor Q6, be used to change level by operational amplifier A MP3 paraphase-amplifying signal.
Above-mentioned purpose, characteristic and advantage with other of the present invention, it is clearer to become when reading the following detailed description in conjunction with the accompanying drawings, wherein:
Fig. 1 is the circuit diagram of the hybrid subscriber match circuit that falls according to preferred enforcement of the present invention.
Fig. 2 is the circuit diagram according to the direct current biasing equivalent electric circuit of the preferred embodiments of the present invention.
Illustrate in greater detail the preferred embodiments of the present invention now with reference to accompanying drawing.
Fig. 1 is the circuit diagram according to the hybrid subscriber match circuit of the preferred embodiments of the present invention.
With reference to Fig. 1, comprise according to the hybrid subscriber match circuit of the preferred embodiments of the present invention: transistor Q1 and Q2 are used to provide electric current; Transistor Q3 and Q4 are used to limit maximum current; Current surveillance resistance R 1 and R2 are used to carry out current feedback work and detect the line current that flows through telephone wire with the restriction maximum current with voltage form; Resistance R 3 and R4 are used to prevent that transistor Q1 and Q2 are saturated; Biasing resistor R5, R6, and R7 are used for determining the threshold value of maximum current and making transistor Q1 and Q2 always be in the service area; Dummy resistance R8 is used to provide bias current to transistor Q1 and Q2, and is saturated when not having line load to exist to prevent transistor Q1 and Q2; Temperature compensated diode D1 and D2, be used to prevent the variation of transistor maximum current threshold value and cause overheated, it is because line current (I
L) cause that the thermal effect of transistor Q1 and Q2 causes; Shunt capacitance C1, C2, C3, and C4 are used for preventing because DC line current power supply generating noise and induction and to the bad influence of call communication; Capacitor C 5 and C6, the DC line current is added to be used for an audio signal (being the AC signal) that receives; Composite impedance ZL1 and ZL2 are used for mating with line characteristic impedance; Amplifier AMP1 and AMP2 are used for receiving and amplifying audio signal; Protection component CR1 and CR2 are used for guard amplifier AMP1 and AMP2 and do not occur overcurrent in the line; Resistance R 11 is used for the line current that flows through resistance R 1 is converted to the input current that is used to detect off hook state; Operational amplifier A MP3 is used for the signal of paraphase-amplification by resistance R 11 inputs; Resistance R 13 is used for definite multiplication factor of passing through the signal of resistance R 11 inputs; Transistor Q6 is used to change the level by operational amplifier A MP3 paraphase-amplifying signal; Resistance R 10 when being used for that telephone bandset is by off-hook during call signal is provided, detecting ring and cuts off voltage; Resistance R 12 is used for becoming the voltage transitions that is detected by resistance R 10 ring to cut off electric current; Capacitor C 7, be used to make operational amplifier A MP3 to be used as low pass filter, like this, its AC multiplication factor reduces greatly, so that remove the AC ripple component that is included in the ring cut-out electric current, and field-effect transistor FET1, be used to make operational amplifier A MP3 when the ringing current supply condition, to be used as low pass filter.
Fig. 2 is the circuit diagram according to the direct current biasing equivalent electric circuit of the preferred embodiments of the present invention.
Explain the operation of the preferred embodiments of the present invention now with reference to Fig. 1 and 2.
Transistor Q1 and Q2 are used for supplying electric current, and transistor Q3 and Q4 are used to limit maximum current.The equivalent electric circuit of Fig. 2 is finished the line current functions of physical supply.Have such structure owing to be used for the circuit of supply lines electric current, wherein plug tip terminal and plug ring terminal are arranged symmetrically, so Fig. 2 only is presented at the equivalent electric circuit of the line current supply of plug tip terminals side.With reference to Fig. 2, line current (I
L) become Ib1*h
FE
Resistance R 5 and R6 form the base current Ib2 of transistor Q2, and it is provided by following mathematical notation formula 1:
[expression 1]
If the resistance R of speech line
LReduce, then line current (I
L) increase, and as line current (I
L) when increasing, the terminal voltage V of resistance R 1
R1Also increase.If voltage V
R1Owing to current feedback reduces (the base current Ib1 that it has reduced transistor Q1), and the resistance R of speech line
LReduce, then the collector voltage V of transistor Q1
CE1Increase, this makes by current Ib 1 increase of resistance R 3.Bias stability is improved by Voltage Feedback, and it has reduced the collector voltage V of transistor Q1
CE1The Another important function of resistance R 3 is to prevent that transistor Q1's is saturated.Particularly, if the resistance R of speech line 3 increase, then line current (I
L) and the collector voltage V of transistor Q1
CE1Reduce.Line current (I
L) the reduction current feedback amount by resistance R 1 that makes reduce and the resistance R of speech line
LIncrease continuously and make line current (I
L) reduce, cause the collector voltage V of transistor Q1
CE1Sharply reduce and reach the saturation region of transistor Q1.At this moment, the base current Ib1 of the transistor Q1 that provides by resistance R 3 will be owing to the collector voltage V of transistor Q1
CReduce and reduce, therefore, stoped that transistor Q1's is saturated.In fact, this stoped on long loop (on this long loop, line resistance R
LIncrease) distortion of AC characteristic.
In addition, maximum current limit is that current feedback by resistance R 1 realizes.Line current I
LIncrease make terminal voltage V
R1Increase, as line current (I
L) reach corresponding to voltage V
R1+V
BE1+V
BE2 become to the state of the voltage that equals V1 numerical value the time, realized the electric current restriction.Yet, if in fact cause electric current restriction, the V of transistor Q1 owing to electric current increases
CEIncrease, this causes and produce power consumption I in transistor Q1
L1*V
CE, cause the thermal effect among the transistor Q1.Because V
BEValue has negative temperature coefficient (that is ,-2.4mV/ ℃) so V
BEReduce with the temperature increase, this causes current limit value to increase.The repetition of this undesired operation causes the error of restricted electric current.As a result, maximum current is more much higher than the restricted electric current of actual needs.In order to prevent this superheating phenomenon, the diode D1 with voltage-temperature characterisitic of forward is connected between transistor Q2 base stage and the ground.In this case, because the forward voltage of diode reduce to because transistor Q1 that the heat that produces causes among the transistor Q1 and the V of Q2
BEIdentical level, so restricted electric current is compensated variation of temperature, like this, restricted electric current can more stably be determined.Though transistor Q1 and Q2 are connected by darlington structure, in fact the base current Ib1 of transistor Q1 is subjected to resistance R 3 restrictions.The purpose of this structure is not to improve voltage gain to the base stage of transistor Q2 by input signal is provided, but improves the gain of the current feedback that is realized by resistance R 1.In other words, as line resistance R
LWhen changing in the scope of confined electric current, confined electric current is in the circuit resistance R
LKeep it constant by transistor Q1 and Q2 during variation.
Simultaneously, the line current function for monitoring drives Q6 and line current is converted to logical signal by the output of amplifying with the paraphase of the change in voltage of resistance R1.The line current function for monitoring of Fig. 1 is also finished ring simultaneously and is cut off function.Particularly, if line current (I
L) increase, then produce a voltage drop, and use by resistance R 11 and the determined gain of R13 the paraphase amplification is carried out in this voltage drop, with driving transistors Q6 by resistance R 1.If transistor Q6 is driven, logical zero (low level) signal outputs to test side DET from the collector electrode of transistor Q6.At this moment, be in the line current (I of the condition of logical zero state corresponding to test side DET
L) determine by resistance R 11 and R12.At line current (I
L) supervision during if ringing current is provided, then the line current monitoring circuit also monitors whether off-hook of this mobile phone.Particularly, ringing relay K1 is switched to resistance R 10, and is added to the plug tip terminal from the ringing current that the ring terminal provides by line resistance RL and terminal telephone set.At off hook state, comprise the line resistance R of the D.C. resistance of terminal telephone set
LDescend sharp, this causes the voltage drop that forms between the two ends of resistance R 10 to increase.This pressure drop is added to the paraphase end of operational amplifier A MP3 by resistance R 12, by paraphase-amplification.Therefore, the output signal of operational amplifier A MP3 becomes and is high level, and is added to the base stage of transistor Q6, so that connect transistor Q6, like this, low level signal is output to test side DET, thus the off hook state of indication telephone set.When the voltage drop of resistance R 10 increases, be output to operational amplifier A MP3 so as the signal that the terminal voltage of resistance R 10 is carried out the paraphase end that paraphase amplifies become for the DC signal of AC bell signal stack, therefore, need reduce the gain of inverting amplifier AMP greatly, so that only detect the DC signal for the AC signal.The reduction of the AC gain of operational amplifier A MP3 has caused reducing of AC gain by the capacitor C 7 that is parallel to resistance R 13, therefore, the DC signal that has the ripple component that is greatly reduced is output from operational amplifier A MP3, makes the ring rupturing operation to carry out exactly.Field-effect transistor FET1 only just connects when ringing relay K1 works, therefore, and under normal condition, to the not influence of line current function for monitoring.At this moment, because the capacitance of capacitor C7 can not be selected as infinitely great numerical value, so, resistance R 11, R12 and R13 should have the big resistance value of hundreds of K Ω, so that capacitor C7 has little capacitance, play the effect of low pass filter.
As mentioned above, be designed to be used in general parts and simultaneously it finishes analog subscriber match circuit identical functions with traditional use transformer or SLIC according to user's match circuit of the present invention, like this, its manufacturing cost can be reduced widely.And, have the on-hook transfer function according to user's match circuit of the present invention, therefore, can be applied to the supplementary service of for example far-end charge, the transmission of calling party's number etc.
Though the present invention is considered to most realistic and describes with preferred embodiment in conjunction with current, should see, the invention is not restricted to the embodiment that disclosed, but on the contrary, its plans to cover the various corrections in the spirit and scope of appended claims.
Claims (11)
1. be used for the analog subscriber match circuit of full-electronic switching system, comprise:
Pair of transistor, promptly the first transistor and transistor seconds are used for giving the user by plug tip terminal and plug ring terminal feeding line current;
Another is to transistor, and promptly the 3rd transistor and the 4th transistor have darlington structure and be connected respectively to first and second transistors, are used to limit maximum current;
A pair of current surveillance resistance is connected to the emitter of the first transistor respectively, is used to realize the current feedback operation so that the restriction maximum current, and is used for detecting the line current that flows through telephone line with voltage form;
First resistance is connected between the collector electrode and the 3rd transistorized collector electrode of the first transistor, is used to prevent that the first transistor is saturated;
Second resistance is connected between the collector electrode and the 4th transistorized collector electrode of transistor seconds, is used to prevent that transistor seconds is saturated;
The biasing resistor group is used for determining the threshold value of maximum current and keep first and second transistors always to be in the service area that the biasing resistor group comprises three resistance that are connected on together;
A pair of first capacitor is used for an AC audio signal that the receives DC line current that is added to;
A pair of composite impedance is used for mating with line characteristic impedance;
The 3rd resistance is used for the line current that flows through the first current surveillance resistance of each current surveillance resistance is converted to the input current that is used to detect off hook state;
Operational amplifier is used for the signal of paraphase-amplification by the input of the 3rd resistance; And
The 5th transistor is used to change the level by operational amplifier paraphase-amplifying signal.
2. the analog subscriber match circuit of claim 1 is characterized in that, also comprises a pair amplifier, is connected to composite impedance respectively, is used for receiving and amplifying audio signal,
3. the analog subscriber match circuit of claim 2 is characterized in that, also comprises a pair of protection component, is used to protect the amplifier that amplifies audio signal not occur overcurrent in the line.
4. the analog subscriber match circuit of claim 3, it is characterized in that, also comprise a dummy resistance, be connected between the collector electrode of the collector electrode of the first transistor and transistor seconds, be used to provide bias current to first and second transistors, saturated to prevent that first and second transistors from occurring when not having line load to exist.
5. the analog subscriber match circuit of claim 4 is characterized in that, also comprises a pair of temperature compensated diode, is connected to the relative two ends of biasing resistor group respectively.Be used to prevent since line current cause first and second transistors that the thermal effect of transistor Q1 and Q2 causes because of the variation of maximum current threshold value cause overheated.
6. the analog subscriber match circuit of claim 5 is characterized in that, also comprises a plurality of shunt capacitances, is used for preventing because DC line current power supply generating noise and induction and to the bad influence of call communication.
7. the analog subscriber match circuit of claim 6 is characterized in that, also comprises the 4th resistance, is used for definite multiplication factor for the signal of importing by the 3rd resistance.
8. the analog subscriber match circuit of claim 7 is characterized in that, also comprises the 5th resistance, when being used for that telephone bandset is by off-hook during call signal is provided, detecting ring and cuts off voltage.
9. the analog subscriber match circuit of claim 8 is characterized in that, also comprises the 6th resistance, is used for becoming the voltage transitions by the 5th resistance detection ring to cut off electric current.
10. the analog subscriber match circuit of claim 9, it is characterized in that, also comprise second electric capacity, be used to make that operational amplifier is used as low pass filter, thereby the AC multiplication factor is greatly diminished, is included in ring with removal and cuts off AC ripple component in the electric current.
11. the analog subscriber match circuit of claim 10 is characterized in that, also comprises field-effect transistor, is used to make operational amplifier A MP3 to be used as low pass filter when the ringing-current supply condition.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR34480/1998 | 1998-08-25 | ||
| KR1019980034480A KR100293948B1 (en) | 1998-08-25 | 1998-08-25 | subscriber interface circuit of electronic exchange system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1250998A true CN1250998A (en) | 2000-04-19 |
| CN1135819C CN1135819C (en) | 2004-01-21 |
Family
ID=19548229
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB991179927A Expired - Fee Related CN1135819C (en) | 1998-08-25 | 1999-08-20 | Subscriber matched circuit for electronic exchanger |
Country Status (2)
| Country | Link |
|---|---|
| KR (1) | KR100293948B1 (en) |
| CN (1) | CN1135819C (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100461632C (en) * | 2005-06-02 | 2009-02-11 | 华为技术有限公司 | Negative feedback circuit, as well as method and device for implementing impedance match of transmission line in chip by using the circuit |
| CN101095232B (en) * | 2003-07-16 | 2010-12-08 | Nxp股份有限公司 | Input stage resistant against negative voltage swings |
| CN105763261A (en) * | 2016-02-24 | 2016-07-13 | 烽火通信科技股份有限公司 | Carrier communication method and carrier communication system based on laser loading modulation |
| CN111917920A (en) * | 2020-08-12 | 2020-11-10 | 上海剑桥科技股份有限公司 | Intelligent loop holding device |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100391885B1 (en) * | 2000-11-07 | 2003-07-16 | 주식회사 연우이앤티 | Subscriber interface circuit of full electronic switching system |
| KR100713369B1 (en) * | 2001-02-28 | 2007-05-04 | 삼성전자주식회사 | Caller id detection central office interface circuit |
-
1998
- 1998-08-25 KR KR1019980034480A patent/KR100293948B1/en not_active IP Right Cessation
-
1999
- 1999-08-20 CN CNB991179927A patent/CN1135819C/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101095232B (en) * | 2003-07-16 | 2010-12-08 | Nxp股份有限公司 | Input stage resistant against negative voltage swings |
| CN100461632C (en) * | 2005-06-02 | 2009-02-11 | 华为技术有限公司 | Negative feedback circuit, as well as method and device for implementing impedance match of transmission line in chip by using the circuit |
| CN105763261A (en) * | 2016-02-24 | 2016-07-13 | 烽火通信科技股份有限公司 | Carrier communication method and carrier communication system based on laser loading modulation |
| CN105763261B (en) * | 2016-02-24 | 2018-08-07 | 烽火通信科技股份有限公司 | A kind of carrier communication method and system based on laser load-modulate |
| CN111917920A (en) * | 2020-08-12 | 2020-11-10 | 上海剑桥科技股份有限公司 | Intelligent loop holding device |
| CN111917920B (en) * | 2020-08-12 | 2022-02-08 | 上海剑桥科技股份有限公司 | Intelligent loop holding device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1135819C (en) | 2004-01-21 |
| KR100293948B1 (en) | 2001-07-12 |
| KR20000014864A (en) | 2000-03-15 |
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