Electronic
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. We recommend that you document this decision (e.g., in a Standard Operating Procedure , or specification document). Records that are required to be maintained under predicate rules, that are maintained in electronic format in addition to paper format, and that are relied on to perform regulated activities.