CN102299744B - Optical module with blaze protection function - Google Patents

Optical module with blaze protection function Download PDF

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Publication number
CN102299744B
CN102299744B CN2011102426467A CN201110242646A CN102299744B CN 102299744 B CN102299744 B CN 102299744B CN 2011102426467 A CN2011102426467 A CN 2011102426467A CN 201110242646 A CN201110242646 A CN 201110242646A CN 102299744 B CN102299744 B CN 102299744B
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CN
China
Prior art keywords
module
optical
optical module
optical fiber
current
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CN2011102426467A
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Chinese (zh)
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CN102299744A (en
Inventor
郑龙
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青岛海信宽带多媒体技术有限公司
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Abstract

The invention discloses an optical module with a blaze protection function. The optical module comprises a light reception assembly used for receiving a light signal, a boost circuit, a current mirror device and an MCU. The boost circuit sends high voltage generated by the boost circuit to a response current output terminal of the light reception assembly through the current mirror device and a current-limiting resistor. The current mirror device receives response current outputted by the light reception assembly, and sends the response current to the MCU after zoom processing. The MCU connects with boost voltage, and adjusts high voltage amplitude outputted by the boost circuit. According to the invention, a high voltage protection circuit is designed at a receiving end of the optical module, so that when a blaze reaches, the light reception assembly is prevented from breakdown and damage, and the optical module is effectively protected. At the same time, through employing a high integrated level transmit-receive one body chip to construct a module circuit, a circuit board dimension is reduced, a SFP interface packaging form is adapted, support of a digital diagnosis function is completed, and maintenance cost of a whole is reduced.

Description

Optical module with highlight protection function
Technical field
The invention belongs to the optical communication technique field, specifically, relate to a kind of optical module of optical fiber receive module being realized the high voltage protective function when receiving terminal input high light.
Background technology
Passive optical network technique (PON) is a kind of point-to-multipoint light access technology, is the best transmission medium of realizing " unification of three nets " and solving information superhighway " last kilometer ", has the integrated service access function of data, voice and video.The PON system is by the OLT(Optical Line Termination of local side, optical line terminal), the ONU/ONT(Optical Network Unit/Optical Network Termination of user's side, network unit/optical network terminal) and be connected to the ODN(Optical Distribution Network between the two, Optical Distribution Network) form.Wherein, ethernet passive optical network EPON is ripe at present light passive access network technology, and the EPON GPON of gigabit progression is the technology of newest standards and commercialization.GPON is due to the advantages such as higher speed, higher access performance and network efficiency, stronger flexibility and scalability can be provided, so more can meet the network insertion application in broadband.In the long run, the GPON system will become main flow, substitute the EPON system.
For current passive optical network, no matter be the OLT of local side or the ONU of user's side, its inside all is provided be used to connecting the receiving terminal of optical fiber with receiving optical signals, i.e. optical fiber receive module.In actual application; when the receiving terminal of optical module receives very strong light signal; tend to because its receiving terminal circuit lacks the problem that the high voltage protective measure causes the breakdown damage of optical fiber receive module; thereby cause the optical module fault; affect the normal operation of passive optical network, brought larger economic loss also for simultaneously network management business and client.
Summary of the invention
The object of the present invention is to provide a kind of optical module with highlight protection function, avoided the problem of the breakdown damage when high light is inputted of the optical fiber receive module in the optical module, improved the reliability of optical module.
For solving the problems of the technologies described above, the present invention is achieved by the following technical solutions:
A kind of optical module with highlight protection function, comprise optical fiber receive module, booster circuit, current mirror device and MCU for receiving optical signals, described booster circuit transfers to the high pressure of generation the response current output of optical fiber receive module by current mirror device and current-limiting resistance; Described current mirror device receives the response current of optical fiber receive module output, and carries out transferring to MCU after the convergent-divergent processing, and described MCU connects booster voltage, and the high pressure amplitude of booster circuit output is regulated.
In order to suppress impulse current, the response current output of described optical fiber receive module passes through capacity earth.
Further, described electric capacity comprises two, be connected between the response current output and ground of described optical fiber receive module, and wherein an electric capacity is encapsulated in described optical fiber receive module.
Further again, with the external electric capacity of the response current output of described optical fiber receive module, be laid on pcb board the position near described optical fiber receive module.
Preferably, the appearance value of two described electric capacity all is less than 1000pF, and withstand voltage is at least 2 times of maximum operating voltage of optical module receiving circuit.
Further, described current-limiting resistance preferred cloth is located at the position of close described optical fiber receive module on pcb board.
Further, described booster circuit connects described current mirror device by filter circuit, and the high pressure that booster circuit is exported carries out the filtering processing.
Preferably, described optical module preferably adopts SFP interface encapsulation form, to support the warm connection function of optical module.Wherein, described SFP interface preferably adopts golden finger connector.
In order to meet the small size designing requirement of SFP packing forms to the optical module internal circuit board, in described optical module, also be provided with laser and be integrated with laser driver and the transceiver chip of limiting amplifier; Described transceiver chip receives the command signal that the user sends, and then controls the luminance of described laser; The back facet current that described laser produces transfers to MCU by a high speed accumulator, with the average light power between the calculated data burst period; The light signal that described optical fiber receive module will receive is converted to electric signal transmission to the transceiver chip, and according to the light signal generating received corresponding response current with it, by sampling hold circuit, export described MCU to, be used to calculating average received power.
Preferably, the back facet current output of described laser connects described transceiver chip by automatic power control circuit, in order to control the luminous power of laser.
Compared with prior art; advantage of the present invention and good effect are: the present invention is by the design of the receiving terminal at optical module high tension protection circuit; thereby when the high light access is arranged, can avoid the breakdown damage of optical fiber receive module, effectively protect optical module, improve the optical communication system reliability of operation.Meanwhile, by optical module being adopted to SFP interface encapsulation form, realized the warm connection function of optical module.And the transceiver chip by adopting high integration and little encapsulation MCU cheaply build modular circuit, have not only reduced the usage quantity of peripheral components, and more wiring space is provided, and have met the small size requirement of SFP packing forms to circuit board; And completed the support of optical module to digital diagnosis function, and then simplified network manager's maintenance work, reduced the maintenance cost of whole optical network communication system.
After reading by reference to the accompanying drawings the detailed description of embodiment of the present invention, it is clearer that the other features and advantages of the invention will become.
The accompanying drawing explanation
Fig. 1 is the circuit theory diagrams of a kind of embodiment of the receiving terminal high tension protection circuit that proposes for the highlight protection function of realizing optical module;
Fig. 2 is the circuit theory diagrams of a kind of embodiment of optical module internal circuit proposed by the invention;
Fig. 3 is the structural representation that adopts the SFP interface of golden finger connector design.
Embodiment
Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in more detail.
Embodiment mono-; the present embodiment easily causes the problem of the breakdown damage of its optical fiber receive module for the receiving terminal that solves optical module when high light is inputted; receiving terminal at optical module has designed a kind of high tension protection circuit; shown in Figure 1, mainly by booster circuit, current mirror device, current-limiting resistance R22 and MCU etc., partly formed.Wherein, the input of booster circuit connects DC power supply VCCT, after DC power supply VCCT was carried out to boosting inverter, output high pressure HV transferred to the current mirror device, and the high pressure of exporting by the current mirror device transfers to the response current output of optical fiber receive module ROSA via the current-limiting resistance R22 of series connection.In optical fiber receive module ROSA, be packaged with avalanche photodide APD and transimpedance amplifier TIA, optical fiber receive module ROSA receives by its inner avalanche photodide APD the light signal of inputting by optical fiber, and then produces corresponding with it response current Ipd.Described response current Ipd is transferred to the current mirror device, and the response current Ipd to input carries out after a certain proportion of convergent-divergent is processed exporting by the current mirror device.In the present embodiment, after described current mirror device can be processed according to the reduce in scale of 5:1 the response current Ipd inputted, by its output output current Io, transfer to the analog-to-digital conversion interface ADC of MCU, perhaps pass through the independently data-interface of analog to digital converter connection MCU, to realize that MCU detects identification to the light signal strength of input, and then produce corresponding control signal and export booster circuit to, regulate with the amplitude of the high pressure HV for booster circuit is exported.When the high light input is arranged; MCU controls the amplitude that booster circuit reduces the high pressure HV of its output; and then maintain the voltage stabilization of the response current output that is applied to optical fiber receive module ROSA, realize the high voltage protective function to avalanche photodide APD in optical fiber receive module ROSA.
In the present embodiment, under the prerequisite of the receiving sensitivity that does not affect optical fiber receive module ROSA and monitoring precision, the resistance of described current-limiting resistance R22 generally is the bigger the better, and recommendation is in 10K Ω left and right.And, when PCB designs, preferably current-limiting resistance R22 is laid in to the position near optical fiber receive module ROSA, more closely better, to improve the protection effect.
In order to suppress rush of current, at the response current output of described optical fiber receive module ROSA, also be connected with ground capacity C23, C24, so that radio circuit to be provided, shown in Figure 1.Wherein, capacitor C 24 can directly be encapsulated in optical fiber receive module ROSA, and its appearance value generally is about hundreds of pF.When capacitor C 23 designs at PCB, reserve pad, adopt the mode external with optical fiber receive module ROSA, and installation position is better the closer to optical fiber receive module ROSA.If surplus sensitivity is enough, can not lay capacitor C 23.When surplus sensitivity is not enough, can weld capacitor C 23, but the suggestion of appearance value is less than 1000pF.Because when carrying out " cold start-up " test, capacitor C 23, C24 just become energy storage device, store superincumbent energy and will, with shortest path from optical fiber receive module ROSA, flowing through, cause rush of current to avalanche photodide APD and transimpedance amplifier TIA.The appearance value is less, and stored energy is less, and corresponding rush of current is also just less.
For the stable high pressure HV exported by booster circuit, the present embodiment also is provided with filter circuit between described booster circuit and current mirror device, preferably adopt by a resistance R 21 and two Π filters that capacitor C 21, C22 form, shown in Figure 1, so that high pressure HV is carried out to the filtering processing.When the described Π filter of design, the general value of resistance R 21 is hundreds of ohm; The appearance value of capacitor C 21, C22 is recommended as 1uF.Simultaneously, it should be noted that: capacitor C 21, C22, C23, C24 all need to consider the selection of electric capacity withstand voltage, recommend withstand voltage should be 2 times of maximum operating voltage of receiving circuit in optical module or more than.
The optical module of the present embodiment preferably adopts SFP interface encapsulation form, to realize the warm connection function of optical module.Wherein, the SFP interface preferably adopts golden finger connector, as shown in Figure 3,10 pin Pin11-Pin20 of positive laying, reverse side is laid 10 pin Pin1-Pin10, by 20 pins are carried out to interface definition, to meet the communicating requirement that is connected of optical module and ancillary equipment.
Because the SFP encapsulation is a kind of undersized packing forms, it has higher requirement to the PCB size of optical module, low cost for the small size to the SFP packing forms and optical module is considered, the present embodiment, when the internal circuit board of the described optical module of design, preferably adopts the transceiver chip U1 that laser driver and limiting amplifier are integrated; MCU preferably adopts little encapsulation, single-chip microcomputer cheaply, then coordinates optical fiber receive module ROSA and laser BOSA composition module circuit, completes the support of optical module to digital diagnosis function, shown in Figure 2.
The present embodiment be take the optical network unit ONU optical module of user's side and is described as example.In Fig. 2, two differential signal input connection data receiving terminal DATA of transceiver chip U1, receive transmission or reception control command and data that the user sends.When the user need to send data, the laser driver in transceiver chip U1 produced bias current Ibias, acts on the light-emitting diode in laser BOSA, drove lumination of light emitting diode.Meanwhile, the data-signal that the user sends is input to laser driver, and then generation electric current I mod is modulated on bias current Ibias, by the conducting degree of controlling light-emitting diode in laser BOSA, change its luminous power, to become light signal to go out by Optical Fiber Transmission data shift signal.
In laser BOSA, diode backlight, according to the strong and weak back facet current Imd that produces corresponding size of light that light-emitting diode sends, feeds back to laser driver by automatic power control circuit APC LOOP, in order to control the luminous power of laser BOSA.The current signal Bias-MON suitable with bias current Ibias is converted to through pull down resistor R1 the ADC port that voltage signal transfers to MCU, after carrying out analog-to-digital conversion, to realize the monitoring calibration to bias current Ibias.
In order to keep stable average light power, need to utilize automatic power control circuit APC LOOP.The back facet current Imd that described automatic power control circuit APC LOOP utilizes the diode backlight of laser BOSA encapsulation to produce, regulate the bias current Ibias that laser driver produces, the reference current that makes the bias current Ibias that detects and its inside set in advance is suitable, certain proportionate relationship, so that constant optical output power to be provided.
In order to realize the monitoring of optical network unit ONU for radiating portion luminous power under burst mode, in described ONU, also be provided with the high speed accumulator, adopt speed-sensitive switch K and storage capacitor C4 to set up and realize, shown in Figure 2.Back facet current Imd by laser BOSA output transfers to the positive pole of storage capacitor C4, the maintenance of sampling, the minus earth of storage capacitor C4 on the one hand via the switch ways of speed-sensitive switch K; Another road ADC port that transfers on the other hand MCU carries out analog-to-digital conversion.When transceiver chip U1 receives the transmission that the user sends or receives control command, convert high level or low level pulse signal to, as the emission enable signal, transfer to the control end of speed-sensitive switch K, control speed-sensitive switch K conducting.Now laser BOSA is driven luminously by transceiver chip U1, produces back facet current Imd, by storage capacitor C4 to the back facet current Imd maintenance of sampling.When the emission enable signal was invalid, back facet current Imd was zero, illustrates that laser BOSA closes.Now, speed-sensitive switch K is controlled to close, and storage capacitor C4 will sample the voltage transmission that keeps to the ADC port of MCU, with monitoring and the calculating of the average light power that happens suddenly.
Detection for descending received optical power, the optical network unit ONU of the present embodiment transfers to the other road ADC port of MCU by the response current Ipd of optical fiber receive module ROSA output by a sampling hold circuit, as shown in Figure 2, to realize ONU accurate monitoring to received optical power under continuous mode.
In Fig. 2, optical fiber receive module ROSA receives by its inner avalanche photodide APD the light signal of inputting by optical fiber, and then produces corresponding with it response current Ipd.After described response current Ipd is converted to voltage signal by the sampling hold circuit composed in parallel by resistance R 3 and capacitor C 3, the maintenance of sampling, and then the ADC port translation that transfers to MCU becomes the digital quantity of internal calibration, in order to realize the monitoring calibration to average received power under continuous mode.In described sampling hold circuit, capacitor C 3 plays the effect of low-pass filtering simultaneously to response current Ipd, with the filtering interfering pulse; The resistance of resistance R 3 need to be adjusted by experiment, the incoming level scope of being supported with the ADC port that meets MCU, and take into full account the precision that meets the SFF-8472 regulation in whole light-receiving dynamic range.
The differential data output OUT of described optical fiber receive module ROSA ,-OUT connects the limiting amplifier in transceiver chip U1 by a road capacitance C1, C2 respectively, after the amplitude of the differential signal that receives is amplified to processing, exports subsequent conditioning circuit to.
In addition, meet the SFF-8472 standard, I need to be provided 2The EEPROM of 256 bytes of C bus access, in the present embodiment, adopt and be built-in with EEPROM and support the MCU of 512 byte transmission to realize, its main I 2C bus (Master I 2C) be used to accessing MCU and On-line Control from I 2C bus (Slave I 2C).
Certainly, circuit assembling structure shown in Figure 2 is applicable in the PCB design of optical line terminal OLT optical module of local side too.
In addition, for the optical module that makes the present embodiment has more monitoring function, the present embodiment preferably adopt have temperature detection, supply power voltage detects and the single-chip microprocessor MCU of bias current measuring ability is set up optical module, thereby realized the real-time monitoring of received optical power under emission luminous power and continuous mode under temperature, supply power voltage, laser bias current and the burst mode to optical module.With with the integrated module of optical transceiver of monitoring function, do not compare in the past, the detection of these monitoring parameters can help the network manager to find out the position of breaking down in optical fiber link, and then simplification maintenance work, improve and improve the stability of FTTH EPON system, promote the competitiveness of EPON system in the FTTH field.
It should be noted that; above-mentioned explanation is not limitation of the present invention; the present invention also is not limited in above-mentioned giving an example, and those skilled in the art make in essential scope of the present invention variation, remodeling, interpolation or replacement, also should belong to protection scope of the present invention.

Claims (10)

1. optical module with highlight protection function, comprise the optical fiber receive module for receiving optical signals, it is characterized in that: also comprise booster circuit, current mirror device and MCU, described booster circuit transfers to the high pressure of generation the response current output of optical fiber receive module by current mirror device and current-limiting resistance; Described current mirror device receives the response current of optical fiber receive module output, and carries out transferring to MCU after the convergent-divergent processing, and described MCU connects booster circuit, and the high pressure amplitude of booster circuit output is regulated.
2. the optical module with highlight protection function according to claim 1, it is characterized in that: the response current output of described optical fiber receive module passes through capacity earth.
3. the optical module with highlight protection function according to claim 2; it is characterized in that: described electric capacity comprises two; be connected between the response current output and ground of described optical fiber receive module, and wherein an electric capacity is encapsulated in described optical fiber receive module.
4. the optical module with highlight protection function according to claim 3 is characterized in that: be laid on pcb board the position near described optical fiber receive module with the external electric capacity of the response current output of described optical fiber receive module.
5. the optical module with highlight protection function according to claim 3, it is characterized in that: the appearance value of two described electric capacity all is less than 1000pF, and withstand voltage is at least 2 times of maximum operating voltage of optical module receiving circuit.
6. according to the described optical module with highlight protection function of any one in claim 1 to 5, it is characterized in that: described current-limiting resistance is laid in the position of close described optical fiber receive module on pcb board.
7. according to the described optical module with highlight protection function of any one in claim 1 to 5, it is characterized in that: described booster circuit connects described current mirror device by filter circuit.
8. according to the described optical module with highlight protection function of any one in claim 1 to 5, it is characterized in that: described optical module adopts SFP interface encapsulation form, and the SFP interface adopts golden finger connector.
9. according to the described optical module with highlight protection function of any one in claim 1 to 5, it is characterized in that: in described optical module, also be provided with laser and be integrated with laser driver and the transceiver chip of limiting amplifier; Described transceiver chip receives the command signal that the user sends, and then controls the luminance of described laser; The back facet current that described laser produces transfers to MCU by a high speed accumulator; The light signal that described optical fiber receive module will receive is converted to electric signal transmission to the transceiver chip, and, according to the light signal generating received corresponding response current with it, exports described MCU to by sampling hold circuit.
10. the optical module with highlight protection function according to claim 9, it is characterized in that: the back facet current output of described laser connects described transceiver chip by automatic power control circuit.
CN2011102426467A 2011-08-23 2011-08-23 Optical module with blaze protection function CN102299744B (en)

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CN102752052B (en) * 2012-07-23 2016-08-17 青岛海信宽带多媒体技术有限公司 Optical module for optical network unit and the method controlling signal of telecommunication output thereof
CN103840884B (en) * 2014-03-27 2019-07-12 上海斐讯数据通信技术有限公司 A kind of chip applied to GPON optical module and BOB
CN104301039A (en) * 2014-09-11 2015-01-21 广西师范大学 Local side light transmitting and receiving device based on light code division multiple access
CN106817164B (en) * 2015-11-27 2019-06-25 青岛海信宽带多媒体技术有限公司 The guard method of avalanche photodide APD and device in a kind of optical module
CN107317637B (en) * 2016-04-26 2020-10-27 苏州旭创科技有限公司 Light receiving module and optical module
WO2018090337A1 (en) * 2016-11-18 2018-05-24 Source Photonics (Chengdu) Company Limited Optical receiver, optical transceiver comprising the same, and method of protecting a photodetector in the optical receiver
CN106708157B (en) * 2016-12-29 2017-10-31 华中科技大学 A kind of APD operating voltages automatic dialing unit and method

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EP0361342B1 (en) * 1988-09-28 1994-12-21 Alcatel SEL Aktiengesellschaft Optical receiver with a widened dynamic range
CN101447830A (en) * 2008-12-26 2009-06-03 武汉电信器件有限公司 Ethernet passive optical network (EPON) optical line terminal photoelectric module with digital supervision and reporting functions
CN201414128Y (en) * 2009-05-04 2010-02-24 青岛海信宽带多媒体技术有限公司 Light network unit supporting digital diagnosis function
CN202168086U (en) * 2011-08-23 2012-03-14 青岛海信宽带多媒体技术有限公司 Optical module having strong light prevention function

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0361342B1 (en) * 1988-09-28 1994-12-21 Alcatel SEL Aktiengesellschaft Optical receiver with a widened dynamic range
CN101447830A (en) * 2008-12-26 2009-06-03 武汉电信器件有限公司 Ethernet passive optical network (EPON) optical line terminal photoelectric module with digital supervision and reporting functions
CN201414128Y (en) * 2009-05-04 2010-02-24 青岛海信宽带多媒体技术有限公司 Light network unit supporting digital diagnosis function
CN202168086U (en) * 2011-08-23 2012-03-14 青岛海信宽带多媒体技术有限公司 Optical module having strong light prevention function

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