The Configuration register must then be set correctly for the software to operate properly. There are two methods used to set the Configuration register. First, the user can manually calculate the desired value and then input that value into the register table, as shown in Equation 1. Alternatively, the user can allow the software to create a recommended window and choose an LSB for the current as shown in Figure 6-7. Both methods accomplish the same goal by using Equation 1, but the method is selected by changing the value in Step 4: Select Configuration Method (as Figure 6-6 and Figure 6-7 show).

Equation 1.

Use Equation 2 to calculate the current LSB by a recommended range in the INA226 data sheet. It is important to note that with either of the methods used, the Current LSB and the Calibration register values are calculated based on the other variable and the R_SHUNT value. See the section, Programming the INA226 in the product data sheet for more information on setting the Calibration register value.

Equation 2.

Figure 6-6 Setting the Configuration Register (Calibration Register)

Figure 6-7 Setting the Configuration Register (Current LSB)