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ADS112C04: ADS112C04 Design Review with Sensor with Current Mode Output

Wayne Chen (Audio AE)
Genius 15950 points

Part Number: ADS112C04
Other Parts Discussed in Thread: ADS122C04

Hi Sirs,

My customer is planning the ADS112C04 to support a sensor device with current mode output as the configuration below.
Would you pls advise if we can use 100ohm Rshunt across AIN2 and AIN3 to achieve the maximum dynamic range with internal reference of 2.048V (2.048/20mA=102.4ohm)?    



Thank you and Best regards,

Wayne Chen
04/20/2020

  • 0
    TI__Guru** 113765 points

    Hi Wayne,

    100 ohm would be within the measurement range of the ADS112C04 and the appropriate value using the internal reference.  It is best to operate slightly less than the absolute maximum positive full-scale range to allow for variations and drift of the sense resistor and any offset and gain error for the ADS112C04.  Also you will only see 15 bits of resolution due to operating in the positive input range only (as AIN2 will always be greater than AIN3).  Depending on required resolution of the current measurement, if greater than 15 bits is required, then I would suggest using the ADS122C04.

    Best regards,

    Bob B

  • 0 in reply to Bob Benjamin
    TI__Genius 15950 points

    Hi Bob,

    Thank you for your elaborate. I updated the block diagram with 100R Rshunt for customer.



    Best regards,

    Wayne Chen
    04/21/2020