• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 82 subscribers
  • Views 641 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.

TMS320F28335: Analog-to-digital conversion formula

David Faustner
Prodigy 40 points

Part Number: TMS320F28335

Hello community,

I am currently dealing with analog-to-digital conversion with TMS320F28335.

It is a 12-Bit ADC with 3V full scale (FSC).

It is stated for instance in SPRUI07 that the digital value is calculated as (4096 / 3V) x AIN (for AIN < FSC) assuming ADCLO = 0V.

In other documents like SPRAAD8A, however, it is stated that the digital value is calculated as (4095 / 3V) x AIN.

Which one is correct? In the worst case an error of 1 LSB is introduced systematically if the wrong formula is used for calculations.

Thanks in advance for clarification.

BR David

 

  • +1
    TI__Guru* 83020 points

    David,

    Thanks for reaching out to the TI E2E forum.  The formula in SPRUI07 is the one we should treat as the correct reference.  You'll note there is an additional parameter that mentions for all voltages 3V or greater will give 4095 output(Max 12-bit number).  

    I'll file a LITBUG against SPRAAD8A to correct that document.

    Best,

    Matthew