Complementary Metal Oxide Semiconductor

What Does Complementary Metal Oxide Semiconductor Mean?

A complementary metal oxide semiconductor (CMOS) is an integrated circuit design on a printed circuit board (PCB) that uses semiconductor technology. The PCB has microchips and a layout of electric circuits that connect the chips. All circuit boards are typically either CMOS chips, N-type metal oxide semiconductor (NMOS) logic, or transistor-transistor logic (TTL) chips. The CMOS chip is most commonly used, as it produces less heat and requires less electricity than the others.


CMOS is used in static RAM, digital logic circuits, microprocessors, microcontrollers, image sensors, and the conversion of computer data from one file format to another. Most configuration information on newer CPUs is stored on one CMOS chip. The configuration information on a CMOS chip is called the real-time clock/nonvolatile RAM (RTC/NVRAM) chip, which works to retain data when the computer is shut off.

Techopedia Explains Complementary Metal Oxide Semiconductor

CMOS holds electrical components found in one circuit or in circuit groups. Each circuit performs a specified purpose that increases a PC’s proficiency. The two most important features of CMOS are low-static electrical power consumption and resistance to high levels of electronic noise.

Integrated on one silicon chip, the CMOS chip consists of a combination of P-type and N-type metal oxide semiconductor field effect transistors (MOSFETs). These circuits allow the implementation of logic gates to form paths to the output from the source of the voltage or the ground. The integrated circuits of CMOS chips are composed of millions of transistors that allow a high density of logic functions.

Compared to a logic controller, a CMOS uses half the power needed to operate dynamic and static positions. It conducts many logic functions that operate only when a unit is being used. This process dramatically reduces the amount of current required to maintain a certain voltage. Processors that use CMOS-based transistors are also more efficient and run at very high speeds without getting too hot. Moreover, CMOS is powered by lithium batteries that can last two to 10 years. Once a battery goes dead, the whole CMOS chip needs to be replaced.


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Margaret Rouse

Margaret Rouse is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical, business audience. Over the past twenty years her explanations have appeared on TechTarget websites and she's been cited as an authority in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine and Discovery Magazine.Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages. If you have a suggestion for a new definition or how to improve a technical explanation, please email Margaret or contact her…