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SN65DPHY440SS: Question about Length from SN65DPHY440SS to AP

Nicky Lim
Genius 3195 points
Part Number: SN65DPHY440SS

Hello,

Retimer =  SN65DPHY440SS

Main AP = QCT chip

Data Rate = Max. 1.3Gbps/lane

 

According to SN65DPHY440SS datasheet, output trace length (SN65DPHY440SS to AP) is 1inch.

1. Does  it have to keep this 1 inch length?

2. What is the maximum length between SN65DPHY440SS to AP?

3. If this length goes longer, what happens the length between SN65DPHY440SS and Camera? 

4. To increase length between Camera to AP, can I use two or more SN65DPHY440SS ICs?

Could you let me get your answer ASAP?

Regards,

Nicky

  • 0
    TI__Mastermind 18655 points
    Hello Nicky,
    ​
    It’s hard to tell maximum length supported. With different transmission materials may have different results, also the clock rate, source signal swing, DE level of source signal, EQ capability of end point receiver will take an effect.

    The DPHY440 supports up to 4dB EQ on its Rx and 2.5dB DE on its TX. These features were intended to some extent to compensate the ISI loss in the channel.

    If customer can measure or simulate the degraded eye diagram, they should be able to get an idea of whether they need ISI compensation from DPHY440.

    As a repeater, DPHY400 is also intended to eliminate the timing skew due to channel differences. As long as the input timing within DPHY440’s spec requirement, it is able to re-align clock and data to improve the system’s timing margin.

    As to repeater on the Rx or Tx it is really a system choice. If one would like to take use of DPHY440’s EQ capability for ISI compensation he may want DPHY440 close to TX. Please be noted if one wants the “de-skew” feature of DPHY440, the repeater should be placed in a location where skew has happened.

    Regards