SBOSAL5 June 2025 INA2227
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
There are two shunt calibration registers for each channel that need to be correctly programmed after each power up for the device to properly report any result based on current. The first step to calculate the value for the calibration register is to calculate the minimum LSB value for the current by using Equation 2. Applying this equation with the maximum expected current of 10A results in an minimum LSB size of 305.17578μA. The INA2227 allows selection of the CURRENT_LSB to be up to 8 times larger than the minimum LSB size. For this example a value of 500μA 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 registers results in a zero value for any result based on current for that channel. Programming these registers is not required for reading shunt voltage, bus voltage or setting corresponding alert limits.