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ADC electrical characteristic Stellaris LM4F212H5QD (REF- and REF+) question

Алексей
Prodigy 10 points

Hello.

I was looking for microcontroller for my laboratory model and if possible with specific adc voltage - minus 2 v to plus 2 v range.

It's not very clear (for me, anyway) which range supports embedded adc of LM4F212? Will it work with 4vpk-pk? 

And if not, is there any other options in family? Anyway i will need some fast speed microcontroller, so i was hoping i can have as much functionality as can in one IC.

Thanks for you attention.

  • 0
    Expert 1635 points

    If you look at the datasheet on page 1273-1274, you’ll see that the minimum voltage for VREFA- is GNDA(0V), and the maximum voltage for VREFA+ is VDDA(or 3.63V), thus no, it will not be possible to measure a negative voltage(or even a 4V peak to peak for that matter) without some analog frontend circuitry.

     

    To my humble knowledge, there are no microcontrollers with internal ADC’s that will let you measure negative voltages, then you’re better off by using a dedicated external ADC, or just build an analog frontend that will convert your analog signal within the boundaries of the internal ADC.