Q. ADPD4100/ADPD4101 power sequence problem?

Hello.
I have a question regarding the ADPD4100/ADPD4101.

The customer made 6 boards of its own and all used ADPD4101.
Three ADPD4101s operate normally, but the other three do not.
(Sometimes it works normally.)

When ADPD4101 does not operate normally, the register is read as 0.

When ADPD4101 does not operate normally, turn off the power and turn it on immediately, and ADPD4101 operates normally.
However, if the power is turned off and turned on after 30 seconds, it does not operate normally.

The initialization sequence described in the errata documentation has already been applied.

Is there any problem with the power sequence or timing?
Please check quickly.

Thanks.

Parents
  • 0
    •  Analog Employees 
    on Jan 4, 2021 2:52 PM

    Hello Leo,

    Thanks for your question! We are in the process communicating with the customer. The customer design has 3V IOVDD and the register 0x00B4 needs to be set accordingly. Please refer to the “IOVDD Supply Voltage Consideration” paragraph on page.25 of ADPD4100/4101 datasheet for register 0x00B4 setting

    Thanks,

    Glen. B

  • Hello Glen.

    Thanks for the quick reply.

    I checked the content in the datasheet.

    I will contact you with further questions.

    Thanks.

    Leo

  • 0
    •  Analog Employees 
    on Jan 5, 2021 1:48 AM in reply to Leo Park

    Hi Leo,

    No problem! Please feel free to reach out if you have any further questions.

    Thanks!

    Glen B.

  • Hi Glen,

    The customer quickly applied the method suggested by Glen, but it still does not work.

    When ADPD4101 does not operate normally, I2C communication does not operate normally.

    (I2C communication is unresponsive.)

    When ADPD4101 does not operate normally, the value including the chip ID is read as 0.

    Is there another way?

    Please check quickly.

    Thanks.

    Leo.

  • 0
    •  Analog Employees 
    on Jan 5, 2021 2:16 PM in reply to Leo Park

    Hi Leo,

    I will do more investigation with the designer on this issue and get back to you ASAP.

    Thanks for your patient.

    Glen B.

  • Hi Glen,

    The power sequence of the ADPD4101 seems to be the cause of the problem.

    When applying the IOVDD voltage 1.1 seconds after applying the AVDD and DVDD voltages, the ADPD4101 does not operate normally.

    (Power sequence: AVDD, DVDD -> Time delay(1.1s) -> IOVDD)

    When voltages are applied to AVDD, DVDD and IOVDD at the same time, ADPD4101 operates normally.

    (At the same time or ~8ms)

    It has nothing to do with the voltage level of IOVDD.

    ++edit

    The customer wants to know the difference in time the ADI can guarantee.

    If the time difference is reduced to 8ms, the board operates normally.

    (This board did not operate normally when the time difference was 1.1 seconds.)

    ++add

    Since 3V is applied to IOVDD, the register value of 0x00B4 is changed to 0x30. Is it correct?

    please check.

    Please check quickly.

    Thanks.

    Leo.

  • +1
    •  Analog Employees 
    on Jan 8, 2021 4:46 PM in reply to Leo Park

    Hi Leo,

    Thanks for waiting! 

    According to our designer, we don't specify the tolerance of the delay between AVDD/DVDD and IOVDD. 

    For register 0x00B4, the default is 0x0050 for default 1.8V IOVDD. Reset bit[6] for 3V IO VDD. So set register 0x00B4 to 0x0010 for 3V IO VDD.

    I emailed my comments to Daniel so Daniel K.  will communicate with the customer.

    Thanks!

    Glen B.

Reply
  • +1
    •  Analog Employees 
    on Jan 8, 2021 4:46 PM in reply to Leo Park

    Hi Leo,

    Thanks for waiting! 

    According to our designer, we don't specify the tolerance of the delay between AVDD/DVDD and IOVDD. 

    For register 0x00B4, the default is 0x0050 for default 1.8V IOVDD. Reset bit[6] for 3V IO VDD. So set register 0x00B4 to 0x0010 for 3V IO VDD.

    I emailed my comments to Daniel so Daniel K.  will communicate with the customer.

    Thanks!

    Glen B.

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