A microcontroller (or MCU for "microcontroller unit) is a small integrated circuit that controls an electronic device. It is similar to a microprocessor but includes memory and other integrated components.

A typical microcontroller includes the following elements:

  1. CPU - ranging from a simple 4-bit processor to a full-blown 64-bit processor
  2. RAM - high-speed volatile memory used to store data temporarily
  3. Flash memory - a type of non-volatile memory used to store data with or without electrical power
  4. I/O interface - serial ports or other connectors for peripheral devices
  5. Wireless communications - transmitters or receivers for sending and receiving wireless signals

Some MCUs are several inches long and wide. Others are extremely small, with a length and width of less than one millimeter. Because microcontrollers are integrated circuits, most are relatively flat. Below are examples of different types of microcontrollers:

  1. an image processor on a digital camera
  2. a digital-to-analog converter (DAC) in a powered speaker
  3. a temperature sensor in a washing machine or dryer
  4. a Wi-Fi transmitter in a smart appliance
  5. a motion tracker in a smartwatch

Nearly all electronic devices include microcontrollers. Many include multiple MCUs that operate in tandem. An automobile, for example, may contain dozens of microcontrollers for sensors, communication, and user interface functions.

Updated August 19, 2021 by Per C.

quizTest Your Knowledge

Which electronic device is most similar to a surge protector?

Correct! Incorrect!     View the UPS definition.
More Quizzes →

The Tech Terms Computer Dictionary

The definition of Microcontroller on this page is an original definition written by the TechTerms.com team. If you would like to reference this page or cite this definition, please use the green citation links above.

The goal of TechTerms.com is to explain computer terminology in a way that is easy to understand. We strive for simplicity and accuracy with every definition we publish. If you have feedback about this definition or would like to suggest a new technical term, please contact us.

Sign up for the free TechTerms Newsletter

How often would you like to receive an email?

You can unsubscribe or change your frequency setting at any time using the links available in each email.

Questions? Please contact us.