- The analog signal is continuous I time and it is necessary to convert this to a flow of digital values. It is therefore required to define the rate at which new digital values are sampled from the analog signal. The rate of new values is called the sampling rate or sampling frequency of the converter.
- The most common ways for implementing ADC are direct conversion, successive approximation, ramp compare, Wilkinson, integrating, delta encoded, pipelined, sigma delta, time interleaved, intermediate FM stage, other types.
- A successive approximation ADC uses a comparator to successively narrow a range that contains the input voltage.
- The values are usually stored electronically in binary form, so the resolution is usually expressed in bits.
- The number of discrete values available, or levels, is assumed to be power of two.
- Resolution can also be defined electrically, and expressed in volts. The minimum change in voltage required to guarantee a change in the output code level is called least significant bit.