As you want to calculate the BW in rheostat mode in a pin, you just need to
analyze the circuit and calculate the input resistance from this pin and the
capacitance of the pin.
I.e., you are using the AD5162 in rheostat mode in conjunction with a discrete
Both resistance are connected in A terminal, B and W shorted.
As you want to calculate the BW in the A pin, you need to calculate the
impedance in this pin, in this case, the parallel between the discrete resistor
and RAW, using Ca as capacitor.