1.4.2 Tips for Measuring Single-Ended Signals

  1. Use a solid, uninterrupted ground plane.

    • If that is not possible, STAR grounding (where each ground return is isolated from each other except at a central point) is recommended

  2. Properly decouple the microcontroller and other digital logic devices.
    • The decoupling capacitors short-circuit high-frequency currents
    • X5R and X7R dielectrics are recommended for these capacitors
    • See the device data sheet for recommended typical values
  3. When interfacing with a noisy analog signal, filtering the signal can improve the Signal-to-Noise Ratio (SNR). Information about digital filtering with the ADC can be found in Sampling Methods.
  4. Shutdown switching logic (clocks, I/O, etc.) when sampling.
    • Shutting down all nonessential switching signals will yield the lowest noise possible for the ADC. Many embedded ADCs can operate in the microcontroller’s sleep mode for this reason. The device data sheet provides more information about the setup and operation of the ADC in sleep.