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SRC4382EVM-PDK: DIR to DIT loopback jitter

Akio Ito
Genius 3595 points

Part Number: SRC4382EVM-PDK

Hi,

A customer measured the jitter of DIR-to-DIT loopback on SRC4382EVM-PDK. The measurement jitter was 3 ns pp. It might be a worse value than the specification. He wants to compare his measurement data with the specification. But their instrument cannot be measured by RSM.
Could you measure the jitter of DIR-to-RXCKO, DIR-to-DIT and DIT-to-DIR loopback by RMS and peak-to-peak?

Best regards,

Akio Ito

  • 0
    TI__Expert 5645 points

    Hi Ito-san,

    i'll have to look into this and will have the measurement data soon. Thanks.

    Best regards,

    Ravi

  • 0 in reply to Ravi Patil
    Genius 3595 points
    Hello, Ravi-san,

    Thank you for your reply and cooperation.

    Best regards,

    Akio Ito
  • 0 in reply to Akio Ito
    TI__Expert 5645 points

    Hi Ito-san,

    I have tried to measure jitter, but he jitter measurement by AP is far away from accurate and reliable. It will be recommended to use specialized scope to accurately measure the jitter and hence the challenge.

    Can you please let us know more info on the applications - for example, the audio data rates, the audio data routing and expected performances, etc.Thanks.

     

    Best regards,

    Ravi

  • 0 in reply to Ravi Patil
    Genius 3595 points

    Hello, Ravi-san,

    Our customer wants to compare his measured EVM data in peak value with TI specified rpm value. I show our customer's measurement peak jitter values below.

    Condition: SRC OFF
    Signal Route: RX1 -> DIR -> DIT -> TX
    Register Settings:
    w e0 7f 00
    w e0 0d 00
    w e0 0e 01
    w e0 0f 22
    w e0 10 00
    w e0 11 00
    w e0 07 f4
    w e0 08 00
    w e0 09 06
    w e0 01 27
    #44.1k/48kHz
    w e0 2d 00
    w e0 07 b4
    #88.2k/96kHz
    w e0 2d 00
    w e0 07 f4
    #176.4k/192kHz
    w e0 2d 00
    w e0 07 94

    Jitter w/i Audio Signal
    Input Sample RateOutput Sample RateSRC4382EVM-PDKSRC4392EVM-PDK
    44.1 kHz44.1 kHz 1.89 ns 1.89 ns
    48 kHz48 kHz 1.70 ns 1.83 ns
    88.2 kHz88.2 kHz 1.47 ns 1.47 ns
    96 kHz96 kHz 1.26 ns 1.39 ns
    176.4 kHz176.4 kHz 1.75 ns 1.70 ns
    192 kHz192 kHz 1.00 ns 1.57 ns

    Jitter w/o Audio Signal
    Input Sample RateOutput Sample RateSRC4382EVM-PDKSRC4392EVM-PDK
    44.1 kHz44.1 kHz 2.84 ns 2.98 ns
    48 kHz48 kHz 2.74 ns 2.96 ns
    88.2 kHz88.2 kHz 2.23 ns 2.32 ns
    96 kHz96 kHz 1.96 ns 2.13 ns
    176.4 kHz176.4 kHz 2.42 ns 2.60 ns
    192 kHz192 kHz 1.17 ns 2.35 ns

    Condition: SRC ON
    Signal Route: RX1 -> DIR -> SRC -> DIT -> TX
    Register Settings:
    #44.1k/48kHz
    w e0 2d 02
    w e0 07 7c
    b
    r e0 32 02
    #88.2k/96kHz
    w e0 2d 02
    w e0 07 3c
    b
    r e0 32 02
    #176.4k/192kHz
    w e0 2d 02
    w e0 07 1c
    b
    r e0 32 02

    Jitter w/i Audio Signal
    Input Sample RateOutput Sample RateSRC4382EVM-PDKSRC4392EVM-PDK
    48 kHz44.1 kHz 1.94 ns 2.08 ns
    48 kHz48 kHz 1.74 ns 1.91 ns
    48 kHz88.2 kHz 1.56 ns 1.56 ns
    48 kHz96 kHz 1.44 ns 1.48 ns
    48 kHz176.4 kHz 1.09 ns 1.14 ns
    48 kHz192 kHz 1.61 ns 1.04 ns

    Jitter w/o Audio Signal
    Input Sample RateOutput Sample RateSRC4382EVM-PDKSRC4392EVM-PDK
    48 kHz44.1 kHz 2.32 ns 3.03 ns
    48 kHz48 kHz 2.22 ns 3.05 ns
    48 kHz88.2 kHz 1.70 ns 2.27 ns
    48 kHz96 kHz 1.65 ns 2.13 ns
    48 kHz176.4 kHz 1.09 ns 1.37 ns
    48 kHz192 kHz 1.78 ns 1.17 ns

    Best regards,

    Akio Ito