CN202268976U - Single chip control optical AGC circuit of cable TV network optical receiver - Google Patents
Single chip control optical AGC circuit of cable TV network optical receiver Download PDFInfo
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- CN202268976U CN202268976U CN 201120412160 CN201120412160U CN202268976U CN 202268976 U CN202268976 U CN 202268976U CN 201120412160 CN201120412160 CN 201120412160 CN 201120412160 U CN201120412160 U CN 201120412160U CN 202268976 U CN202268976 U CN 202268976U
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Abstract
The utility model provides a single chip control optical AGC (Automatic Gain Control) circuit of a cable TV network optical receiver and belongs to the technical field of cable TV. The single chip control optical AGC circuit of the cable TV network optical receiver includes an optical detector D1, inductors L1 and L5, capacitors C1 and C15, an LED D2, resistors R1 and R19, an amplifying tube U1 and U2, a signal coupler Z1, chips Q1 and U3-U4, a control module U5, and sockets JP1 and JP2, wherein the U1 and the U2 are F226 amplifying tubes, the U3 is a PIC16F887-04 single chip microprocessor chip, the U4 is a PE4304 radio frequency digital attenuator chip, the U5 is a GSD-008 display control module, and the Q1 is a 1541 voltage reference chip. The single chip control optical AGC circuit of the cable TV network optical receiver in the utility model has advantages of ultra-low power reception, constant output electrical level, accurate optical power indication, low cost and high safety and reliability.
Description
Technical field
The utility model relates to a kind of Single-chip Controlling light automatic gain control (AGC Automatic Gain Control) circuit that is applied to cable television network optical receiver; Belong to the cable TV technical field, especially the transformation of hybrid fiber coax bilateral network is a kind of based on the cable TV optical transmission device
Background technology
to the end of the year 2009, national wired broadcasting TV user reaches 1.74 hundred million families.On January 13rd, 2010, Premier Wen Jiabao's formal proposition in the Executive Meeting of the State Council of holding accelerates to advance China Telecom's net, broadcasting and television network and the Internet integration of three networks, and the clear and definite timetable of the integration of three networks.On June 6th, 2010, China has passed through integration of three networks pilot scheme, and has confirmed 12 experimental cities and area July 1.After the integration of three networks realized, broadcasting and television network not only can provide TV programme, and the Internet and voice communication service can also be provided.For the Internet and communication network, also can develop business such as Web TV, mobile TV better, share the abundant program resource of broadcasting and television network.It is basic transmission network transformation that SARFT(The State Administration of Radio and Television) requires one of HFC bilateral network transformation, and basic realization FTTB is wherein arranged, and realizes that progressively Fiber to the home.Along with the continuous upgrading and the transformation of hfc plant, fiber optic network replaces coaxial cable rapidly with cheap price, wider coverage, transmission speed and littler failure rate faster.Optical sender and optical receiver just become the key equipment in the network in hfc plant like this, and here I just develop the light automatic gain control circuit that a ultralow luminous power receives cable television network optical receiver according to the development of CHINA RFTCOM Co Ltd of new generation
Summary of the invention
The purpose of
the utility model is the Single-chip Controlling light automatic gain control circuit that a kind of cable television network optical receiver will be provided; It can receive by ultra low power; Output level is invariable, luminous power indication accurately, and cost is low and security reliability is high.
The purpose of
the utility model reaches like this, and a kind of Single-chip Controlling light automatic gain control circuit of cable television network optical receiver comprises photodetector D1, inductance L 1L5, capacitor C 1C15, light-emitting diode D2, resistance R 1R19, amplifier tube U1, U2, signal coupler Z1, chip Q1, U3-U4, control unit U5 and socket JP1, JP2, and wherein U1, U2 are the F226 amplifier tube, and U3 is the PIC16F887-04 singlechip chip; U4 is a PE4304 RF digital attenuator chip, and U5 is the GSD-008 indicative control unit, and Q1 is a MCP1541 voltage reference chip, and the negative pole of photodetector D1 connects an end of inductance L 1, the grounding leg ground connection of photodetector D1; Another termination signal coupler Z1 input of inductance L 1, an end of signal coupler Z1 output connecting resistance R3 and capacitor C 8, the other end ground connection of capacitor C 8, an end of other end connecting resistance R2, R16 and the capacitor C 7 of resistance R 3, the other end ground connection of resistance R 16, capacitor C 7; Another termination direct voltage+24V of resistance R 2, coupler Z1 centre cap connects an end of capacitor C 1,1 pin of another termination amplifier tube U1 of capacitor C 1, the 2 pin ground connection of amplifier tube U1,3 pin of amplifier tube U1 connect an end of inductance L 4, capacitor C 2; Another termination capacitor C 9 of inductance L 4, an end of resistance R 4, the other end ground connection of capacitor C 9, a termination direct voltage+8V of the other end of resistance R 4, capacitor C 10, the other end ground connection of capacitor C 10; One end of another termination inductance L 3 of capacitor C 2,2 pin of another chip termination U4 of inductance L 3, photodetector D1 positive pole connects an end of inductance L 2, an end of the other end connecting resistance R1 of inductance L 2, R15, capacitor C 5; The other end ground connection of resistance R 15, capacitor C 5, an end of another termination capacitor C 6 of resistance R 1,21 pin of chip U3, the other end ground connection of capacitor C 6, chip U3 3,12,13,19,20,23-27,30,31,33-37,42,43 pin be unsettled; 8,9,10,11,14,15 pin of chip U3 connect 2,3,4,9,7,8 pin of control unit U5 respectively, 1 pin of the 16 pin combination hub JP1 of chip U3, and 2 pin of the 17 pin combination hub JP1 of chip U3,3 pin of socket JP1 meet direct voltage+5V; The 4 pin ground connection of socket JP1,5 pin of socket JP1 connect an end of 18 pin of chip U3, resistance R 6, and the Vin pin of the other end of resistance R 6, capacitor C 14 1 ends, chip Q1 meets direct voltage+5V, the Vss pin of chip Q1, the other end ground connection of capacitor C 14; The Vout pin of chip Q1 connects an end of capacitor C 13,22 pin of chip U3, the other end ground connection of capacitor C 13, and 6, the 29 pin ground connection of chip U3,7,28 pin of chip U3 meet direct voltage+5V; The end of the 1 pin connecting resistance R9 of chip U3,2 pin of the other end combination hub JP2 of resistance R 9,1 pin of socket JP2 meets direct voltage+5V, the end of the 44 pin connecting resistance R8 of chip U3; 3 pin of the other end combination hub JP2 of resistance R 8, the 4 pin ground connection of socket JP2, the end of the 32 pin connecting resistance R7 of chip U3, the other end sending and receiving light diode D2 of resistance R 7 is anodal; Light-Emitting Diode D2 minus earth, 38,39,40,41 pin of chip U3 connect 10,11,12,1 pin of control unit U5 respectively, and 5 pin of control unit U5 meet direct voltage+5V, the 6 pin ground connection of control unit U5; The end of the 2 pin connecting resistance R10 of chip U3, the end of the other end connecting resistance R19 of resistance R 10,5 pin of chip U4, the end of the 4 pin connecting resistance R11 of chip U3, the end of the other end connecting resistance R18 of resistance R 11,3 pin of chip U4; The end of the 5 pin connecting resistance R12 of chip U3, the end of the other end connecting resistance R17 of resistance R 12,4 pin of chip U4, the other end ground connection of resistance R 17, R18, R19, the end of the 13 pin connecting resistance R13 of chip U4; One termination direct voltage+3V of 6,9 pin of chip U4, the other end capacitor C 15 of resistance R 13, the other end ground connection of capacitor C 15,0,7,8,10,11,12, the 18 pin ground connection of chip U4, chip U4 1,15-17,19,20 pin meet direct voltage+3V; 14 pin of chip U4 connect an end of capacitor C 3,1 pin of another termination amplifier tube U2 of capacitor C 3, and the 2 pin ground connection of amplifier tube U2,3 pin of amplifier tube U2 connect an end of inductance L 5, capacitor C 4; Another termination capacitor C 11 of inductance L 5, an end of resistance R 5, a termination direct voltage+8V of the other end of resistance R 5, capacitor C 12, the other end ground connection of capacitor C 11, C12, the other end output radiofrequency signal of capacitor C 4 is to preamplifying circuit.
the utility model has used the high sensitivity photodetector, when input optical power during at-5dBm, can guarantee that user's TV signal is normal.Input photodetector luminous power-8～+ during 2dBm, keep output level invariable, when carrying out network design,, can under the prerequisite of not considering luminous power basically, carry out the network rebuilding according to the requirement of network output level.Adopted the digital indicating circuit of accurate luminous power; Show that luminous power deixis circuit has accurately played the effect of light power meter; Can directly read current received optical power; Have great importance for system maintenance,, have the luminous power indicative significance extraordinary especially for the user who does not have light power meter.Make full use of existing network; Optical fiber is extended to user side; EPON is transparent fully to signal transfer protocol, format modulation signal, and network can be expanded according to the growth of customer volume, and the user needs higher quality requirement really from now on; Can be directly optic fibre extension to the user, realize that real optical fiber registers one's residence.Network using optical fiber, network configuration are very simple, between front end and user, have significantly reduced the active electronic equipment, like light station and amplifier, do not need open-air power supply, and the AC backup of supply power is added up RF PON network according to operator and can be reduced by 90% maintenance than hfc plant.Equipment and number of fibers significantly reduce, and the network architecture is simple and clear, and network is realized passive transmission.
Description of drawings
Fig. 1 is the schematic diagram of the utility model.
Embodiment
are referring to figure: Single-chip Controlling light automatic gain control circuit be in certain light receiving power scope (8～+ 2dBm); Import single-chip microcomputer to the signal of telecommunication of optical receiver output through socket JP2; Single-chip microcomputer converts correspondent voltage one tunnel into through program and outputs to indicative control unit; Another road outputs to the RF digital attenuator chip, amplifies invariable signal of telecommunication of output by amplifier tube U2.+ 24V direct voltage is through resistance R 2, capacitor C 7, resistance R 16, R3, capacitor C 8, signal coupler Z1, inductance L 1 input photodetector D1 negative pole; Photodetector D1 work; By 1 pin of the photodetector D1 negative pole output signal of telecommunication through inductance L 1, signal coupler Z1, capacitor C 1 input amplifier tube U1; + 8V direct voltage is input to 3 pin of amplifier tube U1 through capacitor C 10, resistance R 4, capacitor C 9, inductance L 4; Amplifier tube U1 work, the signal of telecommunication that 3 pin of amplifier tube U1 amplify is through 2 pin of capacitor C 2, inductance L 3 input chip U4.The anodal output voltage of photodetector D1 is through 21 pin of inductance L 2, resistance R 15, R1, capacitor C 5, C6 input U3.Chip Q1, U3, U4, control unit U5, socket JP1, JP2, Light-Emitting Diode D2, resistance R 6-R12, R17-R19, capacitor C 13-15 form light AGC control circuit.The 14 pin output signal of chip U4 is through capacitor C 3 input amplifier tube U2; + 8V direct voltage is input to 3 pin of amplifier tube U2 through capacitor C 12, resistance R 5, capacitor C 11, inductance L 5; Amplifier tube U2 work; The signal of telecommunication that the 3 pin output of amplifier tube U3 is amplified to preamplifying circuit, guarantees the invariable signal of telecommunication of light agc circuit output through capacitor C 4 in certain received optical power scope.Wherein U1, U2 are low noise amplifier tube F226, and Z1 is the signal coupling coil, and D1 is a photodetector, and D2 is a light-emitting diode; L1～L3 is signal flatness adjustment air core inductor, and L4, L5 are High frequency filter direct current overcurrent inductance, and C1-C4 is the high frequency capacitance; C5～C15 is a high-frequency filter capacitor, and R1-R14 is a current-limiting resistance, and R15-R19 is a dropping resistor; JP1 is the debug data interface, and JP2 is the data serial ports, and Q1 is a MCP1541 voltage reference chip; U3 is the PIC16F887-04 single-chip microcomputer, and U4 is a PE4304 RF digital attenuator chip, and U5 is the GSD-008 indicative control unit.
the most attractive benefit of Single-chip Controlling light automatic gain control circuit is to reduce the network operation cost.When disposing solution, its following points technical advantage:
1. ultralow luminous power receives: conventional photodetector input optical power-when 3dBm was following, carrier-to-noise ratio (C/N) can sharply descend, and causes user's TV signal mosaic to occur.Single-chip Controlling light automatic gain control circuit has used the high sensitivity photodetector, when input optical power during at-5dBm, can guarantee that user's TV signal is normal.
. output level is invariable: conventional optical receiver input optical power does not change 1dBm; The output signal of telecommunication can change 2dB, Single-chip Controlling light automatic gain control circuit input optical power-8～+ during 2dBm, through internal control circuit; Can keep output level invariable; When carrying out network design,, can under the prerequisite of not considering luminous power basically, carry out the network rebuilding according to the requirement of network output level.
. the luminous power indication: conventional optical receiver has only simple luminous power indication, can't correctly judge current received optical power.Single-chip Controlling light automatic gain control circuit has adopted accurate luminous power indicating circuit; Show that luminous power deixis circuit has accurately played the effect of light power meter; Can directly read current received optical power; Have great importance for system maintenance,, have the luminous power indicative significance extraordinary especially for the user who does not have light power meter.
. cost is relatively low; Be convenient to upgrade expanding: make full use of existing network, optical fiber is extended to user side, EPON is transparent fully to signal transfer protocol, format modulation signal; Network can be expanded according to the growth of customer volume; The user needs higher quality requirement really from now on, can be directly optic fibre extension to the user, realize that real optical fiber registers one's residence.
. fail safe, reliability height; Maintainable good: network using optical fiber, network configuration are very simple, between front end and user, have significantly reduced the active electronic equipment; Like light station and amplifier; Do not need open-air power supply, the AC backup of supply power is added up RF PON network according to operator and can be reduced by 90% maintenance than hfc plant.Equipment and number of fibers significantly reduce, and the network architecture is simple and clear, and network is realized passive transmission
Claims (1)
1.
A kind of Single-chip Controlling light automatic gain control circuit of cable television network optical receiver is characterized in that comprising photodetector D1, inductance L 1-L5, capacitor C 1-C15, light-emitting diode D2, resistance R 1-R19, amplifier tube U1, U2, signal coupler Z1, chip Q1, U3-U4, control unit U5 and socket JP1, JP2, and wherein U1, U2 are the F226 amplifier tube, and U3 is the PIC16F887-04 singlechip chip, and U4 is a PE4304 RF digital attenuator chip; U5 is the GSD-008 indicative control unit, and Q1 is a MCP1541 voltage reference chip, and the negative pole of photodetector D1 connects an end of inductance L 1, the grounding leg ground connection of photodetector D1, another termination signal coupler Z1 input of inductance L 1; One end of signal coupler Z1 output connecting resistance R3 and capacitor C 8, the other end ground connection of capacitor C 8, an end of other end connecting resistance R2, R16 and the capacitor C 7 of resistance R 3, the other end ground connection of resistance R 16, capacitor C 7, another termination direct voltage+24V of resistance R 2; Coupler Z1 centre cap connects an end of capacitor C 1,1 pin of another termination amplifier tube U1 of capacitor C 1, and the 2 pin ground connection of amplifier tube U1,3 pin of amplifier tube U1 connect an end of inductance L 4, capacitor C 2; Another termination capacitor C 9 of inductance L 4, an end of resistance R 4, the other end ground connection of capacitor C 9, a termination direct voltage+8V of the other end of resistance R 4, capacitor C 10, the other end ground connection of capacitor C 10; One end of another termination inductance L 3 of capacitor C 2,2 pin of another chip termination U4 of inductance L 3, photodetector D1 positive pole connects an end of inductance L 2, an end of the other end connecting resistance R1 of inductance L 2, R15, capacitor C 5; The other end ground connection of resistance R 15, capacitor C 5, an end of another termination capacitor C 6 of resistance R 1,21 pin of chip U3, the other end ground connection of capacitor C 6, chip U3 3,12,13,19,20,23-27,30,31,33-37,42,43 pin be unsettled; 8,9,10,11,14,15 pin of chip U3 connect 2,3,4,9,7,8 pin of control unit U5 respectively, 1 pin of the 16 pin combination hub JP1 of chip U3, and 2 pin of the 17 pin combination hub JP1 of chip U3,3 pin of socket JP1 meet direct voltage+5V; The 4 pin ground connection of socket JP1,5 pin of socket JP1 connect an end of 18 pin of chip U3, resistance R 6, and the Vin pin of the other end of resistance R 6, capacitor C 14 1 ends, chip Q1 meets direct voltage+5V, the Vss pin of chip Q1, the other end ground connection of capacitor C 14; The Vout pin of chip Q1 connects an end of capacitor C 13,22 pin of chip U3, the other end ground connection of capacitor C 13, and 6, the 29 pin ground connection of chip U3,7,28 pin of chip U3 meet direct voltage+5V; The end of the 1 pin connecting resistance R9 of chip U3,2 pin of the other end combination hub JP2 of resistance R 9,1 pin of socket JP2 meets direct voltage+5V, the end of the 44 pin connecting resistance R8 of chip U3; 3 pin of the other end combination hub JP2 of resistance R 8, the 4 pin ground connection of socket JP2, the end of the 32 pin connecting resistance R7 of chip U3, the other end sending and receiving light diode D2 of resistance R 7 is anodal; Light-Emitting Diode D2 minus earth, 38,39,40,41 pin of chip U3 connect 10,11,12,1 pin of control unit U5 respectively, and 5 pin of control unit U5 meet direct voltage+5V, the 6 pin ground connection of control unit U5; The end of the 2 pin connecting resistance R10 of chip U3, the end of the other end connecting resistance R19 of resistance R 10,5 pin of chip U4, the end of the 4 pin connecting resistance R11 of chip U3, the end of the other end connecting resistance R18 of resistance R 11,3 pin of chip U4; The end of the 5 pin connecting resistance R12 of chip U3, the end of the other end connecting resistance R17 of resistance R 12,4 pin of chip U4, the other end ground connection of resistance R 17, R18, R19, the end of the 13 pin connecting resistance R13 of chip U4; One termination direct voltage+3V of 6,9 pin of chip U4, the other end capacitor C 15 of resistance R 13, the other end ground connection of capacitor C 15,0,7,8,10,11,12, the 18 pin ground connection of chip U4, chip U4 1,15-17,19,20 pin meet direct voltage+3V; 14 pin of chip U4 connect an end of capacitor C 3,1 pin of another termination amplifier tube U2 of capacitor C 3, and the 2 pin ground connection of amplifier tube U2,3 pin of amplifier tube U2 connect an end of inductance L 5, capacitor C 4; Another termination capacitor C 11 of inductance L 5, an end of resistance R 5, a termination direct voltage+8V of the other end of resistance R 5, capacitor C 12, the other end ground connection of capacitor C 11, C12, the other end output radiofrequency signal of capacitor C 4 is to preamplifying circuit
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| Application Number | Priority Date | Filing Date | Title |
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| CN 201120412160 CN202268976U (en) | 2011-10-26 | 2011-10-26 | Single chip control optical AGC circuit of cable TV network optical receiver |
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| Application Number | Priority Date | Filing Date | Title |
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| CN 201120412160 CN202268976U (en) | 2011-10-26 | 2011-10-26 | Single chip control optical AGC circuit of cable TV network optical receiver |
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| CN202268976U true CN202268976U (en) | 2012-06-06 |
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| CN 201120412160 Expired - Fee Related CN202268976U (en) | 2011-10-26 | 2011-10-26 | Single chip control optical AGC circuit of cable TV network optical receiver |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104506244A (en) * | 2014-12-25 | 2015-04-08 | 四川璧虹广播电视新技术有限公司 | AGC (automatic gain control) control circuit for management type household optical receiving machine |
| CN104506242A (en) * | 2014-12-25 | 2015-04-08 | 四川璧虹广播电视新技术有限公司 | AGC (automatic gain control) control method for management type household optical receiving machine |
-
2011
- 2011-10-26 CN CN 201120412160 patent/CN202268976U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104506244A (en) * | 2014-12-25 | 2015-04-08 | 四川璧虹广播电视新技术有限公司 | AGC (automatic gain control) control circuit for management type household optical receiving machine |
| CN104506242A (en) * | 2014-12-25 | 2015-04-08 | 四川璧虹广播电视新技术有限公司 | AGC (automatic gain control) control method for management type household optical receiving machine |
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| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120606 Termination date: 20131026 |