• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 46 subscribers
  • Views 411 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

ADS5474 EVM question

PV
Prodigy 10 points
Other Parts Discussed in Thread: ADS5474

In my set up, I am collecting the data using a Logic analyzer off of the touch less probe connector on the ADS5474 EVM board. The data coming out of the ADC is offset binary and is centered at 2^(N-1) where N = 14 bits. So, I am expecting the center of the sine wave to be at 8192. Instead, the offset is around 8160 or so. There is a 5 bit offset. Any ideas why this might be?

I have two such EVM boards and both of them show around 5 bits of offset from the expected center of the sinewave.

Thanks.

  • 0
    TI__Expert 6040 points

    HI, PV

    Your number shows actually in the device spec. Please see the data sheet spec table and figure 17 for offset error spec. It is the deviation of output code from mid-code when both inputs are tied to common-mode. The offset error is specified as Max/Min = +/- 11mV (+/-82 LSB, about 6 bits) referenced to the middle scale 8192 due to the limitation of the DC accuracy internally.

    Regards,

    *** Qing