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DAC5681: Please let me check about required specification

Guru 19245 points
Part Number: DAC5681

Please let me check about DAC5681 required spec for two points below. 

①About CLKIN voltage, datasheet P10 is described 0.4V_min and 1.0V_typ.

 Is differential voltage 1.8V, no problem? Is there max voltage?

 If 1.8V is problem, is this point bad influence to phase? (please see below background)

②In the datasheet P28, are CLKIN and DCLKP / DCLKN have required timing spec?

 I didn't find relationship of CLKIN and DCLK.

 If CLKIN and DCLK have large timing gap, is this point bad influence to phase?


・Customer is evaluating DAC5681 for 3~4pcs parallel connection and require sync phase/timing.

・But very rarely, any DAC5681 is delay the phase for 1-clock timing.

 ※Image is attached below. 

・Customer is inquiring the cause of 1-clock delay and revision point of circuit


Best regards,


  • Hi Satoshi
    We're looking into this question and will reply as soon as possible.
    Best regards,
    Jim B
  • Hi Satoshi,

    According to the datasheet the common mode voltage should be set to 0.9V and your typical differential voltage should be 1V as shown in picture below.

    If you are using Va = 1.8V and Vb = 0V which is 1.8 V differential should be fine. The absolute max value for Clock pins is –0.5 to CLKVDD + 0.5.

    CLKIN and DCLK should be coherent phase to each other.

    Have to tried following the startup sequence and Multi-Dac synchronization procedure on page 33 of the datasheet?


    Neeraj Gill