TUSB1002A: TUSB1002A can support how many trace length on the PCB.

Hi,

Please see my inserted response below

1. 1. As specification defined, TUSB1002A only can support 8inch + 2inch for pre-channel and post-channel. If our layout length is 8.6inches, is it not suitable this design ?
      1. The 8in + 2in in the TUSB1002A is an example. With its EQ compensation of 16dB, TUSB1002A can support longer trace length. It is better to use the spreadsheet to calculate the maximum supported trace length.
   2. I try to use the tool “ Rx & Tx trace length budgeting “ that is you provided before. Can I calculate the trace length of “SOC to re-driver” and “re-driver to SOC” just by calculating the RX budget(linear re-driver) and TX budget(linear re-driver)  spreadsheet ? Yes

      1. “SOC to re-driver” can have 11.8inches for layout.

      2. “Re-driver to SOC” can have 8.5inches for layout, but our layout length is 8.6inches, is it not suitable this design.

      3. The calculation parameters as the lists , Max EQ 16dB, Nyquist F 5G, # of blind/buried vias 2(Post channel), # of blind/buried vias 0(Pre-channel), # of through-hole connector 1(Pre-channel), # of ESD protection devices 1(Pre-channel), # of common mode chokes 1(Pre-channel), Trace FR4 width(mil) 4, Pre-channel FR4 Trace length(fixed)(inches) 2.

      4. I don't know what is the setting for RX max CTLE(dB) and CTLE compliance spec@Recepticle(dB) so just set to default.
         1. For the re-driver to SOC, how long the channel can be depends on the SOC RX CTLE EQ and Compliance spec @ receptacle. Both SOC RX CTLE EQ and Compliance spec @ receptacle are system variable and depend on your requirement 
            1. If SOC RX CTLE EQ is higher, which means SOC RX EQ can provide more compensation, then you can have longer post-channel length.
            2. If you want to have higher compliance spec @ receptacle number, then the post-channel length will be smaller.
            3. If I use 3.5dB for both RX MAX CTLE and CTLE compliance spec, then the viable solution is 10.4in.

RX & TX trace length budgeting - TI information - selective disclosure - revF.xlsx

Thanks

David

Hi David,

Thanks for your answer, 

If it is normal, how many "SOC RX CTLE EQ" and "Compliance spec @ receptacle" should be set.

Should "SOC RX CTLE EQ" be set in SOC specification/datasheet?

"Compliance spec @ receptacle" does this have a normal setting value?

Thanks!

Kenny

Kenny

Should "SOC RX CTLE EQ" be set in SOC specification/datasheet? Yes, please consult the SOC datasheet on the maximum EQ its RX can support.

For the Compliance spec @ receptacle" does this have a normal setting value?, we are looking for a value small enough to open up the eye, I would go with 3.5dB.

Thanks

David

Hi Daivd,

Thank you for your feedback.

In this topic can I discuss with you for your competitive re-driver, we want to use TUSB1002A instead.

Their parameters are EQ: 14.6dB but they add FG up to 2.7dB and sw 1000mV, that has any effect? 

Many thanks!

Kenny Lai