Digikey Electronics
Electronic noise is defined as unwanted disturbances superposed on a useful signal that tend to obscure its information content. Noise may be electromagnetically or thermally generated, which can be decreased by lowering the operating temperature of the circuit. Other types of noise, such as shot noise cannot be removed as they are due to limitations in physical properties. Computers, electronic clocks, and programmable logic controllers are constructed of digital circuits. These days analog circuitry may use digital or even microprocessor techniques to improve performance. The study of semiconductor devices and related technology is considered a branch of solid-state electronics. Current Status To most engineers, the terms "digital circuit", "digital system" and "logic" are interchangeable in the context of digital circuits. Most digital circuits use a binary system with two voltage levels labeled "0" and "1". Often logic "0&