Fast Circuit Boards

Appendix DAbbreviations and Acronyms

New acronyms appear in the literature each year. As time goes by, many of these acronyms fall into disuse. In a few cases, meanings may differ depending on the industry where they originate. It is possible for one abbreviation to have several meanings. When this happens, the reader must rely on the intent of the author. As an example, pH can mean hydrogen ion concentration or picohenry. The correct meaning should be obvious in context.

Authors often coin an acronym in an article when a word group is repeated many times. Sometimes, an acronym is used in one company, but it is not used by the industry. These acronyms will not appear in this list.

The following list includes the common abbreviations used in circuit board design, mathematics, electrical engineering, and physics. Fortunately, acronyms that survive rarely conflict with scientific or engineering abbreviations.

Abbreviations that do not conform to present day usage or good practice are not listed. Here are a few of the problem areas. The first letter in many engineering measurement terms is an “m.” In an abbreviation, “m” could stand for milli, micro, or mega. It is good practice to use capital M for mega, small m for milli, and the Greek μ for micro. The letter m can also stand for meter, milliwatt, and mile. In the abbreviation dBm, the m means milliwatt. If m means meter, it can usually be inferred by context.

In an old copy of The Radio Engineers Handbook by Terman, the term ...