The other problem is to integrate analog and digital circuits on the same chip. In this project we will mainly focus on the latter problem. Although digital solutions generally are preferred in electronics design due to design cost, analog circuits are necessary for, e.g., modulating and putting the signal on a transmission line. Note that analog and digital circuits cannot be mixed on the same chip without careful design since they differ in a number of ways. Some of these differences are highlighted below.
Digital circuits are nonlinear, analog circuits are mostly linear.
Analog circuits are much more sensitive to noise and disturbance compared to digital circuits. Digital circuits are generally more noisy than analog circuits. Analog circuits may require less chip area and power for certain applications. Digital circuits can operate at a much lower supply voltage, which is desirable. An interface is needed between the analog and digital domain.