18.4 Operation

The Analog-to-Digital conversion is performed in the following three steps:

  1. Sampling of the input signal.
  2. Capturing of the input signal (holding) and transferring to the converter.
  3. Conversion of the analog signal to its digital representation.

During the sampling of the input signal, the Sample-and-Hold (S/H) circuit capacitor is charged. The sampling time must be adequate so that the capacitor charges to a value equal to the input voltage. At the appropriate time, the input is disconnected from the capacitor, and subsequently, the analog voltage is transferred to the converter. The converter then digitizes the analog signal and provides the result.