Was looking at one of Microchip's reference designs for a Wheatstone bridge sensor.
Was curious about how they justify using 20K resistors feeding the ADC input that calls for a 2.5K maximum source impedance. Granted that the ADC input hold capacitor is 25pF and the output of the instrumentation amp has 1uF diff and common mode caps. I would guess that this is valid for only low sampling rates. High sampling rates would make for a larger load on the ADC input and cause error. Am I correct or missing something?
Aside from the schematic and component data sheets, aren't many details. From the schematic, there are two instrumentation amps for comparison. They both are fed from the came Wheatstone bridge which has some common mode 'noise' injected. The Hexfile that is available is likely programmed into the PIC, no source included. The Thermal Management Utility appears to run on the PC and accesses the demo board.