• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 46 subscribers
  • Views 309 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.

Original question:

WEBENCH® Tools/ADS8900BEVM-PDK: Included item of ADS8900BEVM-PDK

ADS8900BEVM-PDK: difference between rev.A and rev.B

MuRa
Prodigy 40 points
Part Number: ADS8900BEVM-PDK
Other Parts Discussed in Thread: OPA625, THS4551

Hello TI Team,

I ordered two ADS8900BEVM-PDK evaluation boards from digikey at the end of july 2021 and unfortunately received the revision A which has no test point header connector to access the ADC without the control board (PHI controller) to interface for example with an FPGA (which is the case in the project I am working on ).

The first problem I am facing is that I could not find a corresponding user guide document on TI website for revision A to understand the differences between the two board revisions and to find out if it is also limited to the test point header.

www.ti.com/.../ADS8900BEVM-PDK

Could you please send me a link to revision A documents and advise me how to connect the ADC board to interface with an FPGA.
Many thanks in advance.

Best regards,

Muneer

  • +1
    TI__Mastermind 36240 points

    Hello Muneer,

    We recently updated the ADS8900BEVM.  Attached is the link to the original ADS8900BEVM RevA User's Guide.

    sbau269a.pdf

    The primary difference is the input amplifier.  The RevA uses an OPA625 amplifier, which requires a balanced differential input signal.  The Rev B uses the THS4551 fully differential amplifier, which allows either single ended or differential inputs.

    Unfortunately, the RevA EVM is not easy to connect an external MCU or FPGA to the board, which is why I added the header on the RevB.  The best way to connect to the RevA board is to solder small wire jumpers on the IO resistor pads.

    The interface is quite flexible, and you do not need to connect all of the IO pins depending on how you need to use the device.  At a minimum, I recommend connecting to CONVST, /CS, SCLK, SDI, and SDO-0 pins for a typical 4-wire SPI interface.

    If you have additional questions, please feel free to post follow-up questions to this E2E thread.

    Regards,
    Keith Nicholas
    Precision ADC Applications

  • 0 in reply to Keith Nicholas
    Prodigy 40 points

    Hello Keith,

    Thank you for the quick and detailed reply. The link provided is very useful as the schematics are included and a comparison between the two boards revisions will be done easily.
    Adding a header is a good improvement, but soldering should not also be a problem with provided user guide.

    Best regards,
    Muneer

  • 0 in reply to MuRa
    TI__Mastermind 36240 points

    Hello Muneer,

    If you would like a complimentary version of the latest EVM (FDA input amplifier and digital IO header), please let me know and I will see if we can have one sent to you.

    Regards,
    Keith

  • 0 in reply to Keith Nicholas
    Prodigy 40 points

    Hello Keith,

    Thanks for offering a replacement board, but it's not necessary because the guys in our lab informed me that they would solder the SPI interface wires to a small header, as is has been done on rev. B board.

    Best regrads,

    Muneer

  • 0 in reply to MuRa
    TI__Mastermind 36240 points

    Hello Muneer,

    You are welcome.  Glad to hear that you can get your existing boards working.

    Regards,
    Keith