Hi team,
My customer use our 960 and have a question:
The below picture is their POC design insertion loss simulation and they found the IL value drops below -0.35dB when frequency <5MHz. This doesn't meet suggested characteristics in datasheet. Is there any risk and is it acceptable?
Thanks!
Thanks!
Hello Iris,
You are correct that these are our recommended S-Parameter characteristics for the RIN+ PCB traces, leading to the 960 board. However, the main requirements that need to be met are the total transmission requirements in Table 7-6. Transmission Channel Requirements for Coaxial Cable Applications in the 960 datasheet.
This table consists of the required Insertion Loss, Return Loss, and impedance of the entire high-speed channel, from the SER->Cable->DES. The Insertion Loss and Return Loss from each PCB used in the system and the cable will add-up and make-up the total transmission channel characteristics.
If the PCB traces are not meeting the recommended trace limits on one of your boards, then you could try to improve Insertion Loss characteristics on the other PCB board with the serializer on it. Or you can use a cable with less Insertion Loss as well.
As long as you can meet the total transmission channel requirements, then our SER/DES devices should be able to LOCK and transfer video data. If you add all of the Insertion Loss from both PCB boards and the cable, but it still violates the total transmission channel requirements, then there will most likely be errors on the high-speed transmission channel and you will be forced to improve your PCB design or look for a different cable.
I recommend making sure the RIN+ trace on the 960 PCB does meet the recommended characteristics in Table 8-3 in the datasheet early on, so that you are not forced into a difficult situation once other components in the system are finalized and the total channel specs are not met. But if you can confirm that the entire system meets the required channel specs in Table 7-6, then you are fine.
Best,
Justin Phan
