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DS90CF386: DS90CF386_C385A_setup_time_Value

Part Number: DS90CF386
Other Parts Discussed in Thread: DS90C385A

There is confirmation in the DS90CF386 and DS90C385A Specifications.

In DS90CF386 datasheet,
 Output SetupTime:Min 2ns @85MHz
In DS90C385A datasheet,
 Input SetupTime:Min 2.5ns @85MHz

<Question>
 In DS90CF386,
  1: Please tell me the specification of Min output SetupTimeValue for 71.1MHz.
  2: Please tell me the specification of Min output SetupTimeValue for 51.2MHz.
 In DS90C385A,
  3: Please tell me the specification of Min input SetupTimeValue for 71.1MHz.
  4: Please tell me the specification of Min input SetupTimeValue for 51.2MHz.

Please refer to the attached file for details.

DS90CF386_C385A_setup_time_Value.pdf

Best regards,

  • Hi, 

    Regardless of target PCLK, the same minimum limits will apply as what are called out in the datasheet. 

    So the below values are still correct.

    In DS90CF386 datasheet,
     Output SetupTime:Min 2ns @85MHz
    In DS90C385A datasheet,
     Input SetupTime:Min 2.5ns @85MHz

    Regards, 

    Logan

  • Hi, Logan
    Thanks for your help.

    Based on your answer, does that mean that TI's DS90CF386 and DS90C385A cannot be used as a pair?
    I can understand that Input SetupTime: Min 2.5ns in DS90C385A is a fixed value regardless of PCLK.
    However, I have a question about Output SetupTime:Min 2.0ns in DS90CF386.

    For example, at 71.1MHz, the period is about 14ns.
    If the Output SetupTime Min is 2.0ns, then the CLK will be shifted to the left side of the output waveform.
    Please refer to the attached file for details.

    DS90CF386_outputsetup_time_2ns.pdf

    In design, in production and etc..., is there variation data of OutputSetupTime respect to PCLK in DS90CF386?
    I want data as a below
    -------
    In DS90CF386,
      1: Please tell me the specification of Min output SetupTimeValue for 71.1MHz.
      2: Please tell me the specification of Min output SetupTimeValue for 51.2MHz.
    -------

    Best regards,

  • Hi D. 

    Our forums will be down for maintenance through Monday of next week. I'm reviewing your question and will provide feedback when E2E support is resumed on Monday. Thanks for your patience. 

    Regards, 

    Logan 

  • Hi, Logan.

    I am still expecting your response regarding this issue.

    Best regards,

    Thank you.

  • Hi D. ,

    One thing to note though is that the definition for these signals are slightly different. CF386's set-up time is spec'd between the 2V rise of RxOUT to the 2V fall of CLK; whereas 385's is 1.5V to 1.5V. Thus, the 1.5V is a longer time for equal set-up time.

    Regards, 

    Logan