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Negative Analog reference and Analog Input for ADC's

Hi,

Suggest me a device which shall be able to convert negative Analog voltage (0.0 to -3.3) to Digital with minimum 10/12 bit resolution.

Device shall be powered with 5V/3.3V DC or if -3.3V and max current of 20mA shall be tapped.

Above analog range is received from 10k pot.

Regards,

Arun

  • Hi Arunkumar,

    Welcome to our e2e Forum! We have a couple parts which work with a single supply and can accommodate your -3.3V input, one that comes to mind is the ADS8509. Tell us a little more about your application and we might be able to help with some front end analog conditioning to open up a few other options.

     

    Regards,

    Tom

  • In reply to Tom Hendrick:

    Thank you!

    Brief about the Application:

    This is one of the outgoing signal from the Display Unit where -3.3V is given to the 10k pot with reference to the ground. The wiper output voltage need to be measured by the microcontroller to display the actual's. But we unable to measure the range (0 to -3.3V) using inverting amplifier. Instead of building a complicated circuit we planned to go for a negative input ADC. This is the application, therefore your inputs are always awaited.

    Regards,

    Arun

  • In reply to Arunkumar Ramalingam:

    Hi Arun,

    The ADS8509 I mentioned before would have an input range of +/-3.3V, so your 0 to -3.3V would only take advantage of half the full scale input. You might consider doing a level shift of your 0 to -3.3 rather than simply inverting it. That way you would open up the possibilities on the ADC side.

     

    Regards,

    Tom

  • In reply to Tom Hendrick:

    Hi Tom,

    Yes this model helps me.

    Also simple inversion will increase one more ADC rather than negative reference ADC.

    Thank you,

    Arun

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