Switch Mode Power Supply (SMPS) Basics & Diagram

Working Principle of SMPS Power Supply

Like other types of power supply, a SMPS power supply transfers power from a source — usually an AC outlet — to a DC device. What sets the SMPS apart is its ability to regulate the output voltage. It can increase or decrease the output voltage to maintain a constant output regardless of changes in load. This dual ability gives it an advantage over linear regulators, which can only regulate the output down (that is, they can only decrease the voltage, not increase it).

SMPS Operation Diagram

The diagram above outlines how the SMPS operates. An SMPS’s functionality is more complex than that of a linear regulator, but we can break it down into five stages:

1. In the first stage, the incoming AC power runs through a rectifier and undergoes filtration to produce DC

2. The SMPS works at high frequencies, so a high-frequency switch processes the DC signal, which creates a high-frequency pulsating DC signal

3. The power transformer steps down the high-voltage DC signal to a DC signal of the appropriate level

4. The stepped-down DC signal is rectified and filtered to a achieve a steady, constant DV output

5. The control circuitry monitors the output voltage and adjusts the high-frequency switch on-the-fly to ensure a continuous output stream of the desired voltage

Related news articles

Latest News

Sorry, your filter selection returned no results.

We've updated our privacy policy. Please take a moment to review these changes. By clicking I Agree to Arrow Electronics Terms Of Use  and have read and understand the Privacy Policy and Cookie Policy.

Our website places cookies on your device to improve your experience and to improve our site. Read more about the cookies we use and how to disable them here. Cookies and tracking technologies may be used for marketing purposes.
By clicking “Accept”, you are consenting to placement of cookies on your device and to our use of tracking technologies. Click “Read More” below for more information and instructions on how to disable cookies and tracking technologies. While acceptance of cookies and tracking technologies is voluntary, disabling them may result in the website not working properly, and certain advertisements may be less relevant to you.
We respect your privacy. Read our privacy policy here