Hi Sir,
One of our customer's notebook project, due to the design of the SS USB cable is too long, and through the FPC to connect a small board. Now encounter some problem as follows:
When downloading with the USB3.0 port (on the small board, connected to the motherboard through the FPC), using some poor USB cables will cause abnormal interruption, and only a few of the USB cables are OK. The result of eye diagram testing is also failed, but there is no problem in transferring files.
The actual picture is as follows:
We simulated the wiring from the SOC to the EMI device on the motherboard, and the insertion loss was -7.5dB. While the insertion loss of the FPC and the small board could not be simulated due to lack of data, but it is estimate to be about -10dB.
Therefore, we want to add a USB Redriver to the SS USB path to solve this problem. Our idea is to add TUSB1002A near the connector on the motherboard (position 1 above) to see if it can solve the download problem. If not, add another one on the small board.
The principle block diagram is as follows:
Do you have any good suggestions for this problem? We have designed the schematic, and I can send it to you by email to check if there is any problem.
Thanks,
Best Regards
