I'm looking at interfacing a typical Wheatstone bridge sensor to the nRF51822 ADC. This particular sensor only requires a mA or two for excitation and the output fits within the 1.2V precision reference.
My question is regarding an economical, low power interface design between a sensor like this and the nRF51822; Are there any tricks or tips that might make this an easier task?
My current idea is to use a pair of transistors in a current mirror configuration to excite the bridge, and then a small rail-to-rail op-amp to effectively unload and amplify the signal from the sensor and present it to the relatively low impedance ADC input of the nRF51822. I could power the current mirror and the op-amp from a FET controlled by the nRF51822 which would remove power from the sensor and amplifier when not in use.