A series resistance can limit the current on pin IS, as the internal circuit comes to saturation earlier. However, V_ADC should not be considered when calculating RGES (Rseries+R20).
Rather, the calculation should look like this: RGES= (VS– Vsat)/ 6mA RGES= (24V – 2V)/ 6mA = 3666Ω
V_ADC then needs to be considered for the voltage divider: (VS-Vsat)/ RGES= VADC/ R20
https://www.infineon.com/dgdl/Infineon-Application%2BNote-PROFET%2B12V-What%2Bthe%2Bdesigner%2Bshoul... The Application Note, chapter 4.3, provides a better method to calculate the losses in the sense resistor.
