Hi Sir,
Our customer want to use the ONET1130EP on product,
but the Receiver sensitivity with APD ROSA(Low power) with Semtech IC lower than 0.5~1dB.
Currently customer use the NT28L52 TIA ROSA Test , Assert/Dassert difficult to adjust to the optimum point.
Could you please provide your suggestions for me?
Hugo
Hi Hugo,
Sorry for the delay in getting back. Here is my feedback on the question:
For low levels of incoming signals, the internal RX-LOS detection circuitry of the ONET1130EP is typically set to "low" range by setting RXLOSRNG (Bit 0 of Register 4) = 1. With this RXLOSRNG setting, the LOS Assert/De-assert can be adjusted to as low as 10mVpp, through Register 7, RXLOSA[0:5].
Attached is a plot showing the Assert/De-assert values versus Register 7 settings, for RXLOSRNG = 1 for your reference.
Note that the De-assert values are always slightly higher than the corresponding Assert values for the same register settings.
Please check with the customer what settings they're using currently for the RXLOSA and make sure that the RXLOSRNG is set to 1.
Also, the RX output swing VOD of the ONET1130EP can be maximized by setting RXAMP[0:3] to (1111)2.
If the customer has further questions on optimizing the LOS settings or other sensitivity issues, please provide me with more information on the actual application and the target i/p, o/p voltage swings for the ONET1130EP device in the module.
Hope this helps. Do let me know in case of questions.
Thanks!
Best Regards,
Sri
