• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Answers 2 answers
  • Subscribers 46 subscribers
  • Views 657 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.

How to read data from ADS130E08

Divyesh Sinojiya
Prodigy 90 points
Other Parts Discussed in Thread: ADS130E08, ADS131E08

Hi,

I want to read ADC data approx every 3ms.

I want to use START/STOP command and RDATA mode to read data.

Can somebody elaborate that how can I read data precisely? (Timing diagram for when to give START/STOP/RDATA may help)

Source code explaining the same can also help.

Note: I want my ADC chip into powerdown most of the time. What will be powerdown exit time for ADC converter.

  • 0
    TI__Mastermind 23235 points
    Hello Divyesh -
    You can certainly run the ADC in this mode, although the big advantage of delta sigma converters is that it is an oversampling converter which requires history. Starting and stopping the conversions repeatedly will incur a settling time every time you start a conversion.

    The ADS130E08 datasheet should have a discussion of the required signals for reference in the application section. Additionally, there may be some additional information on the startup and interface located in the ADS131E08 datasheet. The timings should be very similar (if not the same) with the differences being the feature set and word size.
  • 0 in reply to Greg Hupp
    Prodigy 90 points

    Hi Greg,


    If I'm ok with the long settle time.

    Will below sequence help me to read proper data?

    • Issue wake-up
    • Wait 125us
    • Issue start command
    • Wait for go to drdy 1 to 0 (I.e negedge)
    • Issue Stop command (Because I want only one sample).
    • Read data through RDATA command
    • Issue standby.

    If no then can you help me out for correct sequence.

    One more question.

    What will be powerdown( via pin PWDN) exit delay for ADS130E08?

    Thanks in advance.


    -Divyesh.

  • 0 in reply to Divyesh Sinojiya
    TI__Mastermind 23235 points

    Hello Divyesh -
    Your procedure is correct, just make sure the timing specs are followed for startup and data settling. The first time you start the device, you can follow the flow chart on page 45. If you wish to stay in RDATA mode, you would not want to issue the RDATAC command in the sequence.
    When using the START and STOP commands, make sure that you are using the appropriate timing as referenced in the START: Start Conversions seciton on page 29. Make sure that you allow time for the data to settle properly after the start command.
    The wakeup time for the device for different modes is provided on page 4 of the datasheet.
    One additional note, if you are planning to use the START/STOP commands, the START pin should be ties low on the PCB

  • 0 in reply to Greg Hupp
    Prodigy 90 points
    Hi Greg,

    Thanks for quick reply.

    Here I'm assuming that DRDY will be de-asserted by ADC once the settle time satisfied. Is it correct assumption?

    In this mode I'm issueing STOP command before RDATA command. Will this create any issues(or operate correctly)?

    (Note : I'm asking this because in RDATA command it is mentioned that "To retrieve data from the device after the RDATA command is issued, make sure either the START pin is high or the START command is issued.")

    -Divyesh.
  • 0 in reply to Divyesh Sinojiya
    Prodigy 90 points
    Hi Greg,

    Any updates for questions above?

    -Divyesh.
  • 0 in reply to Divyesh Sinojiya
    TI__Mastermind 23235 points

    Hello Divyesh -

    The recommended method would be to send the STOP command before the RDATA command once the DRDY is received.