Research And Realization Of Digital Diagnostics Of Sfp Optical Modules

Fiber communication has become the indispensable nervous system of today's information society in these years.In order to provide reliable,high performance light interface to the key application such as optical fiber channel,support day by day complex communication link management,the people widely used the performance monitor technology in the communications system.The digital diagnosis function of optical transceiver module provided one low cost performance monitor method.By digital diagnosis function of optical transceiver module,the network management unit may monitor the temperature,power supply,bias current,transmit power and receive power of optical transceiver module.Through measuring this parameter,management unit can find the fault position of optical link,simplify the maintenance work,and enhance the reliability of system.The paper is under the background of "1.25Gbps single mode optical transceiver module with digital diagnosis function",which is a significant project of Shenzhen Yaguang communications Co.,Ltd.The principle,purpose and design scheme of digital diagnosis function of optical transceiver module are introduced.The total design scheme of optical transceiver testing board,including the hardware circuit seheme,the code for MCU, the communication interface and the IIC communication functions are also given after analyzing the overseas technical development and the existing technical conditions of the company.A series of testing schemes for some important parameters of SFP are given at the last part of this thesis.After times testing,the parameters such as eye-diagram and receive sensitivity of the SFP module are coincident with the design target.The digital diagnostic monitoring is achieved by using a special IC,DS1859.The analog signals which are collected from the LD of TOSA and ROSA are converted to digital signals which are stored in the special area according to SFF-8472.In this way,the DDM function is suceeeded.The IIC inteiface is also provided for the module after programming the MCU on the testing board. The originality of the design is combining testing board with evaluate board.So,it can be used to test and congfigure the module.At last,there is the partial program of MCU in the appendix of the pape.