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.

ADS8557: ADS8557 not work

Part Number: ADS8557

Hi, 

I sent convet signal to ADC but no BUSY reply.

Could anyone kindly provide the initial code of mcu?

Thanks.

  • Hello,

    Unfortunately TI does not have sample code, perhaps another user can share.
    The first thing I would suggest doing, to start off with is to ensure the device is powered up correctly. Also, be sure that the device is not in a reset or powered down state.
    After which, I would check the timing of the digital communication are correct. I would suggest looking at a scope shot of CONVSTx, CS, SDO/I or RD. Also, notice this device has multiple convert starts, thus keep this in mind when debugging.
    One way to make sure you are communicating with the device correctly it to program the registers and then read them back to confirm they are correct.
    Please let me know how you get on
    Regards
    Cynthia
  • Hi Cynthia,

    thanks for your suggestion, but its still failed to bring up.

    i'd checked the power rails: +15v, -15v, +5v, +3.3v.

    and apply the reset signal that is more than 50ns, but it s not to reply busy signal as datasheet P33.

    does it have any other ways to check it?

    thanks.

    brs, Sean

  • Sean,

    How are you using the device? for example serial or parallel?
    Is it on the TI EVM or is it on a different manufactored board?
    Could you share a scope shot of your digital communication? looking at a scope shot of CONVSTx, CS, SDO/I or RD
    Regards, Cynthia
  • Hello Sean,

    Havent heard from you in a while, hope you were able to resolve the issue
    I will go ahead and close this thread. please do come back if you are still having any issues