AC DC Converters, Offline Switchers

AC DC converters and offline switchers are the “power heart” of modern electronic devices. By optimizing topology (such as switching technology) and noise control design, they provide efficient and stable DC power to various loads.

 

1. What are AC DC Converters?

An AC DC converter is a core component that converts alternating current (AC) to direct current (DC). Its operation includes:

 

Rectification: Converting AC to pulsating DC using a diode bridge;

Filtering: Smoothing pulsations and reducing ripple noise using capacitors/inductors;

Voltage Regulation: Maintaining a stable output voltage through linear or switching circuits.

 

AC/DC converters are widely used in applications requiring a stable DC power supply, such as home appliances, industrial equipment, and medical devices.

 

2. What are Offline Switchers?

Offline switchers are a high-efficiency subcategory of AC/DC converters that utilize switching power supply technology:

 

Operating Principle: High-frequency switching transistors (such as MOSFETs) are rapidly switched on and off, coupled with a transformer to adjust the voltage. The DC output is then rectified and filtered.

Advantages: Significantly higher efficiency than linear regulators, smaller size, and suitable for high-power applications (such as computer power supplies and chargers).

Key Design Considerations: Low-ESR tantalum capacitors or parallel electrolytic capacitors are required to suppress switching noise.

 

3. Technical Classification and Selection Points‌

Type	Features	Applicable Applications
Linear Regulators	Simple structure and low noise, but with lower efficiency	Low-power precision equipment
Switching Regulators	High efficiency (>80%), compact size, requiring noise suppression	High-power equipment (such as industrial power supplies)
Isolated Design	Electrically isolates input/output circuits for improved safety	Medical equipment and communication base stations