TUSB1064: TUSB1064 setting for 5G LFPS test

Gary

TUSB1064 does not control LFPS swing level, they can reduce the LFPS swing level by reducing the LFPS amplitude from the source.

Thanks
David

Hi David,

 Do you mean they have to adjust Keysight equipment....?

 They test CYUSB4347's demo board and no LFPS issue. Do I have to ask customer to bypass TUSB1064 on board to confirm it?

Gary

Gary

Not the Keysight equipment. Is CYUSB4347 the source? If so, does it have the ability to reduce its LFPS swing?

Thanks
David

Hi David,

 CYUSB4347 is U3 Hub and TUSB1064 connect up-stream of Hub. 

 Test equipment <--> type-c DFP ----------- type-c UFP <--> TUSB1064 <--> CYUSB4347

Gary

[11/26/18]LE>unlock for reply

Gary

I heard this issue is still open and not being resolved. If you look at the LFPS signal in the failed compliance report, the failed amplitude is 1.2V which is the max LFPS amplitude per the spec. The hub does not need to set the LFPS to the max level, it can set it to 1V. Have they done this? Would you please provide the latest update on this one.

Thanks
David

Hi David,
We have asked local TI FAE to provide TUSB1064 EVM to clear the issue. Will let you know the result after customer feedback. Thanks.
BTW, why our switch can't disable LFPS compliance function and always scale the signal?

Best regards,
Gary

Gary

TUSB1064 does not scale the LFPS signal. The amplitude of LFPS signal can only be changed by the source of LFPS, which in this case, is the Cypress hub. Please reach out to Cypress support asking them on how to change the LFPS amplitude.

Thanks
David

Gary

Would you please provided a status update on this one?

Thanks
David