LOGIC GATES

Electronic digital circuits are also called logic circuits because with the proper input, they establish logical manipulation paths. Each signal representing a variable carrying one bit of information. Logic circuits that perform the logical operations of AND,OR and NOT are called gates. These gates are blocks of hardware that produce a logic - 1 or logic-0 output signal if input requirements are satisfied. There are four names used for same type of circuits: Digital circuits, switching circuits, logic circuits and gates.

Logic Gates

Boolean Algebra The mathematical system of binary logic is better known as Boolean, or switching algebra. This algebra conveniently used to describe the operation of complex networks of digital circuits. Designers of digital systems use Boolean algebra to transform circuit diagrams to algebraic expressions and vice versa. Boolean algebra may be used to express mathematically the interconnections among network of gates.

INTEGRATED CIRCUITS An integrated circuit is a small silicon semiconductor crystal, called a chip, containing electrical components such as transistors, diodes, resistors and capacitors. The various components are connected inside the chip to form an electronic circuit. There are two types of packages the flat package, and the dual-in-line package. The dual- in –line package is the most widely used type because of the low price and easy installation on circuit boards. See figure 1.8 in book.

INTEGRATED CIRCUITS The envelope of the IC package is made of plastic or ceramic. Most packages have standard sizes, and the number of pins ranges from 8 to 64. IC’s are classified in two general categories: Linear Digital Linear IC’s operate with continuous signals to provide electronic functions such as amplifiers and voltage comparators. Digital integrated circuits operate with binary signals and are made up of interconnected digital gates.Here we are concerned only with digital integrated circuits.