Circuit

This describes the physical connection of devices: transistors etc.

Take an inverter for example, an inverter implements the logic function: .

Figure 1. inverter symbol

We can implemente an inverter using two MOS, one NMOS and one PMOS, as shown below:

Figure 2.  An inverter implementation using complementary CMOS circuit

As we can see from the above figure, two MOS connect together according to the manner show by the figure. In the ideal case, when in = “1”, the inverter would output out = “0”; when in = “0”, the inverter would have out = “1”. That means we implement the logical function between in and out:

Figure 3.Input and output waveforms of an inverter

1. Open source resources

Staticfreesoft published a free design tool for circuit design, and open source code:

http://www.staticfreesoft.com/productsFree.html

2. Web pages

The following link to a book on CMOS circuit design:

http://cmosedu.com/cmos1/book.htm

3. Citations

 <<Digital Integrated Circuits-A design Perspective>> from UC Berkeley professor Jan M. Rabaey is one of standard books on CMOS logical circuit design.