• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 46 subscribers
  • Views 90 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.

ADS8688A: Negative voltage A/D conversion output value

mikami.daiki
Prodigy 20 points
Part Number: ADS8688A
Other Parts Discussed in Thread: ADS8688,

Tool/software:

When a negative voltage is input to the ADS8688, an A/D conversion value in the vicinity of “0B***h” is output.
This A/D converter can be set to various voltage ranges,
The circuit uses a range of 0V to 5.12V.
When a negative voltage is input, it is expected to stick to “0000h”, but in reality, values between “0B00h” and “0BFF” are output. The datasheet does not list negative voltage output, so please let me know the output specifications.

  • 0
    TI__Guru**** 175201 points

    Hi Mikami,

    The ADS8688A provides a straight binary output based on the selected voltage input range.  Please refer to Figure 85 (page 35) in the datasheet.  If you selected the '0 to 1.25 x Vref' input range, the output code should clip at 0x000 for any input below ground (0V).