nRF51822 ADC

[Fiske]

We have a application that use the ADC of nRF51822 to detect a variable resistance (schematic is attached). The current passing through the variable resistor should be around 1uA, It means that the R1and R2 should be very large. Up to I know the ADC should have minimum biasing current. Is the nRF51822 ADC applicable in below application

[Roger Clark]

See this answer

devzone.nordicsemi.com/.../

" The impedance of the input voltage source, i.e. the device that generates the voltage to be measured by the ADC input pin, must be low, preferably within 1 kohm"

Your circuit will have an input impedance of approx 300k ohms

i.e 300 times more than recommended by Nordic