Section 1.2
Advantages and Limitations of Digital Techniques

Advantages

1. Easier to design. Exact values of voltage or current are not important, only the range (HIGH or LOW) in which they fall.
2. Information storage is easy.
3. Accuracy and precision are greater.
4. Operation can be programmed. Analog systems can also be programmed, but the variety and complexity of the available operations is severely limited.
5. Digital circuits are less affected by noise. As long as the noise is not large enough to prevent us from distinguishing a HIGH from a LOW.
6. More digital circuitry can be fabricated on IC chips.
   

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Limitations

There is really only one major drawback when using digital techniques:
The real world is mainly analog.
Most physical quantities are analog in nature, and it is these quantities that are often the inputs and outputs that are being monitored, operated on, and controlled by a system.

To take advantage of digital techniques when dealing with analog inputs and outputs, three steps must be followed:

1. Convert the real-world analog inputs to digital form. (ADC)
2. Process (operate on) the digital information.
3. Convert the digital outputs back to real-world analog form. (DAC)

The following diagram shows a temperature control system that requires analog/digital conversions in order to allow the use of digital processing techniques.