Question about the voltage measured at DRVDD when only AVDD power is applied in AD9648

Due to the occasional abnormal operation when the AD9648 is powered on, the circuit has been changed to a circuit that applies the power of AVDD and DRVDD separately.

So, after AVDD is applied first, after clock is stabilized, DRVDD power is applied to perform soft reset.

However, I measured DRVDD with only AVDD applied, and I got the result as shown in the figure below.

Before applying DRVDD, can you see the reason for the abnormal voltage as shown in the picture above?

Also, please advise if measuring abnormal voltage before applying DRVDD voltage could affect the operation of AD9648.

Thank you.

Top Replies

    •  Analog Employees 
    Apr 22, 2021 +1 verified
    Before applying DRVDD, can you see the reason for the abnormal voltage as shown in the picture above?

    it very well could be, given that the chip has analog and digital circuits all in one piece…

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  • +1
    •  Analog Employees 
    on Apr 22, 2021 12:52 PM
    Before applying DRVDD, can you see the reason for the abnormal voltage as shown in the picture above?

    it very well could be, given that the chip has analog and digital circuits all in one piece of silicon. i dont understand why there is about 17s delay between when AVDD is ON, to when DRVDD is ON. seems excessive. 

  • My customer is concerned about whether the AD9648 may have a problem with the voltage measured before the above DRVDD is applied.
    (It is a situation where the board was revised in the product being mass-produced, so the customer is sensitive to the above.)

    Can you confirm that there is no problem with AD9648 operation by the voltage measured before DRVDD is applied?

    Waiting for your answer.

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  • My customer is concerned about whether the AD9648 may have a problem with the voltage measured before the above DRVDD is applied.
    (It is a situation where the board was revised in the product being mass-produced, so the customer is sensitive to the above.)

    Can you confirm that there is no problem with AD9648 operation by the voltage measured before DRVDD is applied?

    Waiting for your answer.

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