I want to design a circuit to measure a very low voltage at a high current (Vmax = 250V DC). For this i want to choose the AD8479 because it has high input resistors which minimize the current loss through the device to GND.
In the Datasheet, Figure 12 shows that the maximum common range at Vsupply =5V is around 210V. Figure 11 shows the common range of 600V with Vsupply =15V.
Is the area between 5V and 15V linear? My application does not have 15V available, but a 9V is there. If the device is supplied with 9V is it possible to take 250V + a bit of reserve?