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ADS8515: ADS8515 Analog to Digital Converter internal voltage reference of 4.096V

Part Number: ADS8515
Other Parts Discussed in Thread: OPA320, ADS8339, ADS8864, ADS8695, ADS8685

Hi,

I have a question on how ADS8515 internal voltage reference of 4.096V is generated? Because I am trying to use this Analog to Digital converter because it was on previous design, but I am not using it to it full +/-10V input voltage scale. My input voltage will be from 0 to 2.5V so the scaling have to change and I am not using it to it full potential. I will then need a voltage reference of 1.25V for my ADC, but this ADC have a voltage reference of 4.096V and can I disable the internal voltage reference? Or somehow reduce it? Or maybe there is a different ADC that can satisfy my need?

Any suggestion would be helpful.

Thank you,

Ken 

  • Hi Ken,

    ADS8515 does not fit your new requirement, it has a internal 4.096V voltage reference with a very narrow range(4.076V to 4.116V). Also, the external reference voltage range is from 3.9V to 4.2V(4.096V typ is expected as well).

    There are two solutions:

    1. Amplifier(OPA320 etc.)+ADS8864(400ksps) or ADS8339(250ksps)+external 2,5V reference, both ADCs can support 2.5V external voltage reference.

    2. ADS8685(500ksps) single device solution, it has an internal voltage reference but the lowest input range is 0-5V and it will lose dynamic range.However, ADS8685 does not need an external amplifier to drive. The 18-bit version ADS8695 (500ksps) can be used as well.

    The first solution is a better solution. Please let me know if you have any question, thanks.

    Regards,

    Dale