Most of the modern op amps is satisfied for these requirements, the inverting inputs of this op amps should be connected to the Vcc/2 (half of power supply voltage). In addition, the comparator must have a high input and low output impedance. Input voltage which can range from zero up to power supply voltage (Vcc) converts to parallel additional binary code at the outputs of the converter.įor normal operation of the ADC requires that the inverter-comparators A1-A4 should be able to switch when the voltage on their inputs equal to Vcc/2 and an error must be no more than Vcc/(2 n-2) (n - number of bits of binary code at output), and the output voltage of the comparator in on/off states should be close to zero and to the Vcc. The simplest Analog to Digital Converter (ADC) can be constructed as shown in Figure 1.