• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 31 subscribers
  • Views 673 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

AFE4404: ADC_RDY pin's voltage dropdown

Koh
Prodigy 30 points
Part Number: AFE4404

Dear E2E Community,

I try to control AFE4404 by MCU.But ADC_RDY pin's output voltage lower than MCU threshold voltage.

I think that the cause is ADC_RDY pin's drive current.

Could you tell me information for ADC_RDY pins's electrical specification  more than datasheet(7.5).

[Application infomation]

・Supply 2.5V to IO_SUP,RX_SUP(AFE4404) and MCU.

・Connect ADC_RDY(AFE4404) to GPIO(MCU)

・GPIO is INPUT setting

Thanks,

Koh

  • 0
    TI__Genius 12555 points
    Hi Koh,

    Level of ADC_RDY is governed by IO_SUP, so if you are giving same IO_SUP to MCU there should not be a problem.
    Also, can you please remove the connection of ADC_RDY to MCU and confirm (by probing) that ADC_RDY is pulsing as expected.

    Regards,
    Prabin
  • 0 in reply to Prabin Yadav
    Prodigy 30 points
    Hi Prabin Yadav,

    Thank you for comment.
    Unfortunately,I can't remove connection of ADC_RDY to MCU.Because connection line hide to package of AFE4404 and MCU.
    Could you tell me specification of IO_SUP current. Is drive current of IO_SUP 20 uA only?

    Regards,
    Koh
  • 0 in reply to Koh
    TI__Genius 12555 points
    Hi Koh,

    I don't think this is problem of current driving capability of IO_SUP. Also if the GPIO of MCU (where ADC_RDY is connected) is configured as input why would it need current greater than 20uA. By the way IO_SUP can drive upto few hundreds of uA.
    I think something is fundamentally wrong in your setup. Do you see LEDs connected to the TX pins of AFE4404 glowing?


    Regards,
    Prabin
  • 0 in reply to Prabin Yadav
    Prodigy 30 points

    Hi Prabin Yadav,

    This issue solved.The cause is that I used a broken probe.
    I retested ADC_RDY ｖoltage with normal probe(another one).ADC_RDY pin rose up to 2.43V.

    Thank you for your cooperation.
    Regards,
    Koh