AnsweredAssumed Answered

About ADN2855 data packet dropout

Question asked by ryan.xia@excelpoint.com.cn on Apr 23, 2015
Latest reply on Apr 27, 2015 by Dongfeng

Hello every engineers !

Our customers had bought over 100pcs ADN2855 for their GPON products . They used the ADN2855 to detect the burst data . But there are over 15% chips will happen the data packet dropout situation .

 

For example , In the normal situation , they test the data in their test software .   The up data is 100 , the down data should be 100 . But  many chips 's  down are only  98 , these chips also can work , but the test result is not very accuracy .

 

We had ruled out the keep condition or  static electricity reasons ,

 

As below is the design schematics about ADN2855

 

 

 

When thsy test the BPD of the OLT optical module , Test the  signal of  ADN2855 DATAV_N , somtimes when the BPD in the high level ,the DATAV_N Will suddenly become high , (when the optical module is lighting , the status of DATAV is wrong , the data packet dropout will happen  ) and the reset command can't  control the ADN2855 .

So we think ,    maybe the circuit of ADN2855  or the circuit of optical module have some questions  ,  or the clock of CDCE62005 have some questions .  Please kindly help us analysis .

 

The below picture is the signal of DATAV_N

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