+ Post New Thread
Results 1 to 9 of 9
  1. #1
    Full Member level 2
    Points: 1,192, Level: 7

    Join Date
    Mar 2016
    Posts
    147
    Helped
    0 / 0
    Points
    1,192
    Level
    7

    ADC maximum value issue

    Hello All,

    I am interfacing ADS1501 12 bit ADC with controller. I am getting proper o/p form 0 to 0x7fffh with variable POT of 1k,5ketc.

    Now thing is that 12 bit ADC should get result o/p upto 0x1000h but I am not getting that much of value.

    My supply voltage is 5V and I have used 10kohm resistors to pull up SDA and SCL lines.

    Please support me.

    •   AltAdvertisement

        
       

  2. #2
    Advanced Member level 4
    Points: 8,209, Level: 21
    Achievements:
    7 years registered
    paulfjujo's Avatar
    Join Date
    Jun 2008
    Location
    France 01120
    Posts
    1,324
    Helped
    269 / 269
    Points
    8,209
    Level
    21

    Re: ADC maximum value issue

    Now thing is that 12 bit ADC should get result o/p upto 0x1000h but I am not getting that much of value.
    hello,

    unsigned 12 bit cover :
    0 to 4095
    0 to 0x0FFF (less than 0x1000)

    is the adc result an unsigned 12 bits value ?
    else you will get
    -2048 to + 2047



  3. #3
    Full Member level 2
    Points: 1,192, Level: 7

    Join Date
    Mar 2016
    Posts
    147
    Helped
    0 / 0
    Points
    1,192
    Level
    7

    Re: ADC maximum value issue

    How to find the same?



    •   AltAdvertisement

        
       

  4. #4
    Super Moderator
    Points: 77,915, Level: 68
    Achievements:
    7 years registered
    Awards:
    Most Frequent Poster 3rd Helpful Member

    Join Date
    Apr 2014
    Posts
    15,793
    Helped
    3593 / 3593
    Points
    77,915
    Level
    68

    Re: ADC maximum value issue

    Hi,

    How to find the same?
    Reading the datasheet.

    Klaus



    •   AltAdvertisement

        
       

  5. #5
    Full Member level 2
    Points: 1,192, Level: 7

    Join Date
    Mar 2016
    Posts
    147
    Helped
    0 / 0
    Points
    1,192
    Level
    7

    Re: ADC maximum value issue

    Hello everyone,

    Can you please suggest me single ended o/p ,I2C compatible ADC
    24bit,16bit

    I dont need negative values.

    It will be more helpful for me.



  6. #6
    Super Moderator
    Points: 77,915, Level: 68
    Achievements:
    7 years registered
    Awards:
    Most Frequent Poster 3rd Helpful Member

    Join Date
    Apr 2014
    Posts
    15,793
    Helped
    3593 / 3593
    Points
    77,915
    Level
    68

    Re: ADC maximum value issue

    Hi,

    Best is do it on your own.

    Go to a distributor's internet site and use their interactive ADC selection guide.
    Or go to any ADC manufacturer and do the same.

    Klaus



  7. #7
    Full Member level 2
    Points: 1,192, Level: 7

    Join Date
    Mar 2016
    Posts
    147
    Helped
    0 / 0
    Points
    1,192
    Level
    7

    Re: ADC maximum value issue

    I have done the same.

    I am not geeting any adc having following specs,

    ADC-16bit and 24bit

    Only positive scale required.

    do not need negative values.

    single ended o/p ,I2C compatible ADC

    may you guys may know better option for the same. please suggest.



  8. #8
    Advanced Member level 4
    Points: 8,209, Level: 21
    Achievements:
    7 years registered
    paulfjujo's Avatar
    Join Date
    Jun 2008
    Location
    France 01120
    Posts
    1,324
    Helped
    269 / 269
    Points
    8,209
    Level
    21

    Re: ADC maximum value issue

    hello

    just in the middle !
    18bit ADC MCP3421 (1 chanel ) with PGA (1,2,4,8) (programmable Gain Amplifier)
    18-Bit Analog-to-Digital Converter
    with I2C Interface and On-Board Reference

    i tested this device (version 4Ch)with a 18F258 MPLAB C18



    •   AltAdvertisement

        
       

  9. #9
    Super Moderator
    Points: 77,915, Level: 68
    Achievements:
    7 years registered
    Awards:
    Most Frequent Poster 3rd Helpful Member

    Join Date
    Apr 2014
    Posts
    15,793
    Helped
    3593 / 3593
    Points
    77,915
    Level
    68

    Re: ADC maximum value issue

    Hi,

    I am not geeting any adc having following specs
    Nonsense.
    Farnell shows more than 100 ADCs with I2c and 16...24 bits of resolution.

    Some of them have unsigned output data.
    But most of them have binary twoīs complement format. As long as you donīt apply negative voltage you donīt need to do anything.
    And in case you want to avoid negative digital values, then itīs just one line of code....

    Klaus



--[[ ]]--