FAQ: What Is a Switching Power Supply Best Used For?

What is a switching power supply?
A switching power supply is one of the two major types of power supply design utilized in electronics products. These power supplies are characterized by the use of precise switching that allows for designs to accommodate DC to DC, DC to AC, AC to DC and frequency conversions.

What is the difference between a switching power supply and a SMPS?
Research and development of power supplies that used “switching” to improve efficiency over conventional linear power supplies dates back to the 1950s with early devices that utilized vacuum tubes; however, the first patented use of the term, “switch-mode power supply,” was in 1976 by Howard Scott of RCA. Today, the terms, “switching power supply” and “switch-mode power supply” (SMPS), are generally used synonymously.

What types of switching components are used in switching power supplies?
In contrast to linear power supplies that typically employ diodes, SMPSs utilize precise switching to control duty cycle operation. Therefore, transistors that allow for enhanced control are most often employed.

Where are switching power supplies used?
Switching power supplies are primarily used in digital systems such as telecommunication devices, computing equipment, audio equipment, mobile phone chargers, medical test devices, arc welding equipment and automotive chargers.

What is a switching power supply adapter?
Power supplies are essentially converters. Typically, they convert one or more parameters from supplied power to the parameter type and level required by a load or connected circuit. A power supply adapter allows for the utilization of a power supply whose output was not specifically designed for the utilized input. Power supply designs may consist of the conversion circuitry only or may consist of conversion and adapter circuitry on the same board.

What are the types of switching power supply design?
The most common design types for switching power supplies are:

Buck
Boost
Buck-Boost
Forward
Flyback
Push-Pull
Half Bridge
Full Bridge
What are the most significant challenges when designing switching power supply boards?
Precise control of the switching action is a critical design requirement for switching power supplies. However, this switching action creates high frequency and noise. For PCBAs, lower RF frequencies are not a significant concern. Yet, for high-speed board design, special considerations, such as trace lengths and terminations, board impedance, and material type, must be addressed.