Digital Systems: Principles and Design

497ADC, DAC and AnalogDigital Mix Interfaces

A digital circuit is also actually an analog circuit but is one where we consider only sig-

nals in terms of 1s and 0s, where the 1 and 0 represent two discrete states of voltages and

currents. (Section 1.1).

Therefore, the circuit of Figure 20.5 also works like a digital switch. (i) When we con-

nect either state 1 or 0 at one end X, we shall get state 1 or 0 another end, Y respectively,

only, whenever the switch closes by applying a control voltage of about V

+

. (ii) No logic

output appears at other end if the switch opens by V



.

IC chips 4016, 4051, 4052, 4053, 4066 have the circuit of Figure 20.5 as ...