What does PFC mean in SMPS datasheets?

PFC stands for Power Factor Correction. It is a feature in modern, high-quality SMPS units designed to improve energy efficiency from the perspective of the power grid.

• What is Power Factor? In simple terms, Power Factor (PF) is a measure of how efficiently a device draws power from the AC mains. An ideal device has a PF of 1.0. Standard power supplies without PFC are "non-linear loads"—they draw current in short, sharp pulses instead of a smooth sine wave. This creates a poor power factor (around 0.6-0.7) and introduces harmful harmonic distortion back into the power grid.
• Why is it important? Poor power factor puts unnecessary strain on the utility grid's wiring and transformers. Because of this, many regions (like the European Union) legally require devices over a certain power level (e.g., 75 watts) to have PFC.
• What does PFC do? A Power Factor Correction circuit is an active electronic circuit placed at the input of the SMPS. Its job is to actively shape the input current waveform to match the shape and phase of the input voltage waveform. This makes the SMPS appear as a simple resistive load to the power company, resulting in a much higher power factor (typically 0.95 or greater).

When you see "Active PFC" on a datasheet, it signifies that the SMPS is a modern, efficient design that meets regulatory standards and draws power cleanly from the wall outlet.