TUSB522P: RE-Driver application questions

David Desrosiers55

Prodigy 30 points

Part Number: TUSB522P

I’m investigating the TUSB522P for a re-driver application and have a few questions, please find them below.

Can a TUSB522P be utilized on the host and device side of the cable simultaneously?
Is using 1 or 2 devices in series transparent to the USB host / device?
Any data you can share on the max. cable length that can be driven assuming:
1. 1 redriver at the host
2. 1 redriver in the middle of the cable
3. 2 redrivers (1 host, 1 device)
Any minimum AWG spec. required for the superspeed data lines with this re-driver in use?
Can the TUSB522P be used in combination with a USB 3.0 Hub? Any areas of concern?

TUSB522P: USB 3.0 Redriver

over 7 years ago

0 Luis Omar Moran over 7 years ago

TI__Genius 16150 points

Hi David,

We have tested cascading only for 2 TUSB522P. Basically, the major issue would be turnaround time in USB which is set for a max cable length of 5m between devices. Another limitation, that is a bigger concern would be keeping the VBUS voltage within spec over the cable length. Theoretically, there should not a limit on the number of TUSB522P cascaded.

Best Regards,
Luis Omar Moran
High Speed Interface
SWAT Team

0 David Desrosiers55 over 7 years ago in reply to Luis Omar Moran

Prodigy 30 points

Where is the optimal placement? Can you share any data on how much insertion loss a single TUSB522P can recover across a cable?

0 Luis Omar Moran over 7 years ago in reply to David Desrosiers55

TI__Genius 16150 points

Hi David,

Is depending of the characteristics of your system. Could you provide the length trace from the host to the device, please?

Thanks,
Luis Omar Moran
High Speed Interface
SWAT Team

0 David Desrosiers55 over 7 years ago in reply to Luis Omar Moran

Prodigy 30 points

Hi Luis,

Trace length on the PCB to the TUSB522P would be small, <2".

My main concern is that we may be at about 8dB of insertion loss on the cable and I need to know how much loss I can gain back based on equalization / pre-emphasis assuming a TUSB522P on either end of the cable.

Thanks,
David

0 Undrea Fields over 7 years ago in reply to David Desrosiers55

TI__Genius 11020 points

Hi David,

The TUSB522P has up to 9dB EQ gain, along with added de-emphasis (Up to -6.2dB) from the Tx output of the re-driver on the other end of the cable. We generally only perform cable testing during the compliance testing with the standard 3m cable defined in the test spec. For testing different loss profiles we use test boards with different trace lengths to insert loss.

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TUSB522P: RE-Driver application questions