The V_IN range for the high voltage sensing is remaining very small at 250 mV in order to allow for high-value resistances providing isolation to the chip. With the V_IN being fixed, the external R_SENSE resistor choice is crucial in order to get the right accuracy at the desired voltage range. Shown here in Table 3 is the V_RMS ranging from 50 to 240 V_RMS, the R_SENSE recommended goes from 1.8 to 13 kΩ. It is very important to pick the right values in order to keep the balance between high voltage isolation at the input, but also the right output voltage swing that takes advantage of the full internal ADC dynamic range. Otherwise, without an accurate voltage measurement, the power calculation is not accurate either.