7.1 Analog signals

7.1.1 Analog-to-Digital Conversion

Among the most common types of sensors are those that produce an analog voltage proportional to the physical variable being measured. An analog-to-digital converter (ADC) transforms the analog value to one of a discrete number of states.

For the purposes of illustration, the nonlinear transfer function of an ideal ADC with just eight states is shown in figure 7.2. The input voltage range of this quantizer is from \(-10\) V to \(+10\) V. The output states are indicated by the binary numbers from \(000\) to \(111\). This arrangement of input voltages and output states is referred to as "offset binary."

Figure 7.2: Transfer function of an ideal 3-bit ADC.

In general, the resolution of such a binary coded ADC is defined by the number …