SBOSAA2 December 2022 INA232
PRODUCTION DATA
The shunt calibration register needs to be correctly programmed at each VS power up in order for the device to properly report any result based on current. The first step is to calculate the minimum LSB value for the current by using Equation 2. Applying this equation with the maximum expected current of 10 A results in an minimum LSB size of 305.17578 μA. The INA232 allows selection of the CURRENT_LSB to be up to 8 x larger than the minimum LSB size. For this example a value of 500 μA is used. Applying Equation 1 to the Current_LSB and selected value for the shunt resistor results in a shunt calibration register setting of 1280d (500h). Failure to set the value of the shunt calibration register will result in a zero value for any result based on current. Programming this register is not required for reading shunt voltage, bus voltage, or setting alert limits.