My plan is to use an ADS1115 ADC to read a low impedance 0-5V output signal from a level transducer. The ADC data sheet gives guidance for ADC input filtering. This data sheet, and even other input filter design notes all assume a relatively high frequency input signal (High frequency relative to my application).
My application is a level transducer that will mostly be 0v for the majority of its life. I will only be monitoring the input signal for a high level event. If a high water level were to occur, it would happen very slowly, it would take over 10 minutes just for the level to increase an inch. Once the level reaches a high threshold; however, level reading accuracy is critical.
My design is power critical, runs on battery. I chose my sampling rate to be 64 samples per second. The entire system will wake from sleep, take a few samples, average them, and go back to sleep (sleep duration will be a few seconds). The transducer is mounted directly onto PCB via one or two inches of wire. Industrial environment, very noisy environment as wel.
Given this application, is a RC circuit really necessary? I would imagine just removing the resistor from the RC circuit and letting just capacitor filter all AC noise would be enough for my application? I would of course still use the differential capacitor as per the data sheet. Or would it be better to make a RC filter with a very low cut off? That was my original plan, but the use of precision resistors and required class 1 caps would eat into board space and allotted budget; I didn't want to go this route unless it would be necessary.
Thank you for taking the time to read!