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ADS131M03-Q1: Maximum Absolute Input

Part Number: ADS131M03-Q1

If we supply 3.3V

Table 8-1 implies for a gain of 1, the maximum voltage that can be read is 1.2V

Customer Support told us that was for differential and to use absolute (from Table 3) would allow maximum 3.3V and to get absolute input (instead of differential) we needed to connect the negative of the input to ground and feed the voltage measurement into the positive.

We have a demoboard (4 channel version though) and when we ground the negative and feed in 1.3V, only read 1.2V 

When I followed up with customer support they suggested posting the inquiry to E2E so we could 

"directly communicate with our device specialist in E2E forum. Our device specialist has access to board that can you check and replicate your query."

  • Hi Chris,

    if you ground the negative input of an ADC channel of ADS131M03-Q1 then the positive input can only swing between GND - 1.2V and GND + 1.2V. The differential voltage between the positive and the negative input needs to be <= VREF = 1.2V when using gain = 1.

    Regards,
    Joachim Wuerker