SBOS644C February 2013 – March 2018 INA231
Connect the input pins (IN+ and IN–) to the sensing resistor using a Kelvin or 4-wire connection. These connection techniques make sure that only the current-sensing resistor impedance is detected between the input pins. Poor routing of the current-sensing resistor commonly results in additional resistance present between the input pins. Given the very low ohmic value of the current-sensing resistor, any additional high-current-carrying impedance causes significant measurement errors. Place the power-supply bypass capacitor as close as possible to the supply and ground pins. Make sure the NC pins (B2 and C2) are not connected to anything.