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TM4C129 ADC ref voltage

Shreyas Belgave
Intellectual 400 points


Hello,

I have some basic questions regarding the ADC, I am confused about it.

Why the Sample Sequencer is required?? why there are 4 SS's?? what is exact role of it???

and

when we are giving analog input then What is the Ref voltage?? in what range the input is taken??  

  • 0
    Guru 47900 points

    Some (basic) answers follow:

    To begin - this is not (our) fathers' MCU - nor its ADC.   (if you are seeking "past" standards - ARM proves not best choice.)

    Sample Sequencers provide increased flexibility while offering several advantages over past, simpler ADC implementations.

    Four was the number chosen by this vendor and/or ARM.   These vary in the number of "back to back" conversion "steps."   These steps are automatically controlled (sequenced) by the MCU.  The Sequencers range between: 8, 4 & single "steps" - you are free to choose the one you feel best suited to your needs/application.

    Ref. Voltage is defined (usually) w/in the ADC Chapter w/in the MCU data-sheets.   And it is (always) defined w/in the (rear) ADC Specifications of those same data-sheets.   As a general rule - the Ref. Voltage may be input at levels up to the MCU's Vdd.   As the Vdd voltage is subject to much digital switching - it is unlikely to be fully "quiet."   Thus a Ref. Voltage - of proper value and "cleanliness/stability" may be used in place of the (ease) of tieing Vdd to the Analog Vdd.

    The MCU manual is the best place to expand your knowledge & confidence w/these ADCs.   The nature of these questions signals you've not spent much time w/in the ADC Chapter...

  • 0 in reply to cb1
    Intellectual 400 points

    Sorry Sir.... I dint  get  u..

  • 0 in reply to Shreyas Belgave
    Guru 47900 points
    Read again - I'm mobile - net is "in/out."