SN65LVPE512: SN65LVPE512 problem

Khoa Duy Tran

Part Number: SN65LVPE512
Other Parts Discussed in Thread: TUSB522P, SN65LVPE502A, TUSB7340,

Hi, we are currently using the LVPE512 part on multiple legacy systems. About in this year, we plan to put two or more LVPE512 parts in cascade in a new design very soon, so can we do it? If not, why? What if we use the new TUSB522P part?

I saw Moises Garcia replied to Dror, "We had seen some interoperability issues with LVPE512 and placing them in cascade was not possible.TUSB522P is an improved version of LVPE512, it fully supports USB3.1 Gen1(5 Gbps)"

We would like to have answers from TI by a 1st week of May 2018 we are appreciated. Waiting for a reply.

over 6 years ago

0 Michael.Walker over 6 years ago

TI__Mastermind 19720 points

We do not usually have applications that need two or more LVPE512s in cascade. What application do you have where you need them in cascade? I am not quite sure if that E2E post was correct but will check.

0 Undrea Fields over 6 years ago in reply to Michael.Walker

TI__Expert 7540 points

The TUSB522P can support a cascaded topology. The issue with cascading the LVPE512 was related to detecting the receiver termination of the connected LVPE512. Since the LVPE512 will only enable it's Rx termination after it has detected the Rx termination of a connected device on both upstream and downstream ports, having the LVPE512's directly connected resulted in neither device enabling termination. The TUSB522P has improved logic that enables cascading.

0 Khoa Duy Tran over 6 years ago in reply to Undrea Fields

Prodigy 80 points

5811.Two USB3 repeaters in Series.pptx

Michael and Undrea, Thank you for the prompt reply and the detailed explanation. That is a good news for using more than one TUSB522P added in a cascade topology. Do you expect any other signal quality and timing problem with a cascade topology?

Attachment is the system USB diagram, includes some questions I have for TI (Undrea answered Item3.) I hope the diagram is helpful. (FYI, SN65LVPE502A is currently used on one of the cards in this system and we plan to switch to TUSB522P later.)

0 Michael.Walker over 6 years ago in reply to Khoa Duy Tran

TI__Mastermind 19720 points

From the diagram you will only need one TUSB522P the second repeater is only compensating 4 inches of loss. Which there will not be that much loss from that length of FR4.

0 Khoa Duy Tran over 6 years ago in reply to Michael.Walker

Prodigy 80 points

Just clarifying my understanding, do you mean 40" or 4" of loss? I asked for 40"-45" FR4 loss path between the host and a USB cable connector with adding a single repeater is working?

0 Michael.Walker over 6 years ago in reply to Khoa Duy Tran

TI__Mastermind 19720 points

To clarify one TUSB522P can compensate for both the 40"-45" prechannel loss as well as the loss across the 3 m cable.

0 Khoa Duy Tran over 6 years ago in reply to Michael.Walker

Prodigy 80 points

Mike, Thank you for reply. Great! Now I have other questions:
1) what the driver De-emphasis and receiver Equalization settings should be recommended by TI for the TUS522P with the 40"-45" FR4 loss on the TI host controller side?
2) I have same question on the driver De-emphasis and receiver Equalization settings for the TUS522P with the 3m cable loss on the cable side?
3) I have the question on the driver De-emphasis and receiver Equalization settings for the host TI TUSB7340 controller driver w/ 40"-45" FR4 loss?

0 Michael.Walker over 6 years ago in reply to Khoa Duy Tran

TI__Mastermind 19720 points

The TUSB522P settings for the channel that will receive from the 40"-45" FR4 will be 9BD on EQ and -3BD of DE. The TUSB522P settings for the that will recieve from the 3 meter cable will be 6DB of EQ and -6.2DB of DE. The DE on the TUSB7340 should be -3DB.

0 Khoa Duy Tran over 6 years ago in reply to Michael.Walker

Prodigy 80 points

You provided me the recommended DE setting on the TUSB7340 with the 40"-45" channel loss, but what about the Adaptive Equalization setting?

0 Michael.Walker over 6 years ago in reply to Khoa Duy Tran

TI__Mastermind 19720 points

You should use the Fully Adaptive, FTC Normal setting for the Receiver Equalizer Configuration.

0 Khoa Duy Tran over 6 years ago in reply to Michael.Walker

Prodigy 80 points

Thank you Michael for the prompt rely. I read the SN65LVPE512 datasheet which contains some simulation results for some good long channels, but the TUSB522P datasheet does not. Does TI have any simulations done for the TUSB7340 and TUSB522P combo which you would share with me?

0 Michael.Walker over 6 years ago in reply to Khoa Duy Tran

TI__Mastermind 19720 points

No, we do not have simulations of that combo of devices.

0 Khoa Duy Tran over 6 years ago in reply to Michael.Walker

Prodigy 80 points

Does TI have any simulations of the TUSB522P part, like TI had for the SN65LVPE512 part? Thanks,

0 Michael.Walker over 6 years ago in reply to Khoa Duy Tran

TI__Mastermind 19720 points

We do not have simulations but you can use the IBIS-AMI models to do simulations

0 Khoa Duy Tran over 6 years ago in reply to Michael.Walker

Prodigy 80 points

It is good if I had the simulation results of the TUSB522P part from TI for comparison. Okay, if I need more questions about the part I would contact TI again. Thank you much for your great support and bye!

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SN65LVPE512: SN65LVPE512 problem