Applying analog-to-digital converters
Many types of sensors produce a response that can be measured as a voltage. An embedded processor measures a voltage with an analog-to-digital converter. An analog-to-digital converter (ADC) is a processor peripheral that samples an analog voltage and produces as output a digital data value corresponding to the voltage at the time of the sample.
An ADC is characterized by the number of bits in the digital measurement word, the voltage range of the input signal, the time it takes for a conversion to complete, and other performance parameters such as accuracy and measurement noise.
As shown in Figure 2.2, an analog voltage can vary continuously over time, and can take on any value within its operating range. The output of an ADC is only available at discrete points in time and can only take on the limited number of values dictated by its resolution. In this simplified example, the ADC produces measurements three bits wide with output values...
