TUSB212: PCB Layout Guidelines for USB Redriver placement

Anbarasan K

Part Number: TUSB212

Need help on USB Retimer option. My Host says the routing length of USB2.0 trace is 10cm .Where should i place the retimer TUSB212? Does the device capable of retrieving the lost signal on the trace if place beyond the acceptable limit. I need to travel 30cm .Kindly suggest on how and where to place my redriver on PCB.

over 3 years ago

0 Anbarasan K over 3 years ago

Prodigy 20 points

0 JMMN over 3 years ago in reply to Anbarasan K

TI__Guru 60870 points

Hello,

How long is the flex PCB? And how long is the trace on the secondary board? Is the USB 2.0 block on the secondary board a USB device or a USB port?

Regards,

JMMN

0 Anbarasan K over 3 years ago in reply to JMMN

Prodigy 20 points

0 JMMN over 3 years ago in reply to Anbarasan K

TI__Guru 60870 points

Hi,

I would place the redriver on the host side close to the flex PCB connector. I would recommend setting the redriver to the lowest setting to start. While the host or device may only be rated to drive 5-10 cms of PCB trace, it is expected to be able to drive a 5M cable after that amount of PCB trace, only minimal redriving may be necessary.

Regards,

JMMN

0 Anbarasan K over 3 years ago in reply to JMMN

Prodigy 20 points

Hi,

It means i can place the Redriver on the Motherboard near the Intel Host side.? Since the drive strength of the BCM-Device side in Daughter board is just 10cm , Wont the signal be lost if i place the Redriver at a distance of 24.5cm apart(Flex + Daughter board Trace Length) .

Regards,

Anbarasan K

0 JMMN over 3 years ago in reply to Anbarasan K

TI__Guru 60870 points

Hi Anbarasan,

I would expect the BCM-Device is rated to drive 10 cm of trace to a USB connector, and from there it is expected to drive 5M of USB cable so it should be able to drive 22 cm of cable. If this is not the case, then place the redriver on the daughterboard near the connector. I do not recommend placing the redriver right next to the host or device since the TX signal quality will already be ideal at that point, it is better to place it near the connector.

Regards,

JMMN

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TUSB212: PCB Layout Guidelines for USB Redriver placement