ABSTRACT

The designation "digital logic circuit family" refers to digital integrated circuit (IC) that are manufactured using the same technology and have the same circuit structure, such as the Complementary metal-oxide-semiconductor (CMOS) logic family. The circuit modules of the same family can be readily connected together, but interconnecting modules from different families require special interface circuits because of differences in the voltages representing logic 1 and logic 0. The CMOS inverter embodies most of the salient features of the CMOS logic circuit family. BiCMOS is considered next as a logic family that is basically CMOS based but has a bipolar junction transistor output stage that enhances the current-drive capability. The design of CMOS gates that implement a given logic function is based on the preceding observations. Low-power CMOS is becoming increasingly important for reducing battery drain in portable devices, and for ameliorating problems associated with power dissipation and cooling in large ICs.