Primary Functions of the LLC Module

Primary Functions of the LLC Module:

Efficient DC-DC Conversion: Effectively converts the high DC voltage (e.g., 400V) output from the PFC stage into stable low voltages (e.g., 12V, 5V, 3.3V) required by the load.

Provides Electrical Isolation: Completely separates the input and output sides via a high-frequency transformer, ensuring user safety.

Achieves high power density: Higher switching frequencies enable the use of smaller magnetic components (transformers, inductors).

Simple analogy: The LLC module acts like an “advanced transmission.” It receives the regulated, stable high-voltage DC from the PFC “traffic cop,” then ‘downshifts’ it into various low-voltage DC outputs required by the equipment in an extremely smooth, nearly frictionless (loss-free) manner. Its operation is remarkably “silky smooth.” .
Summary and Interconnection

In a typical switching power supply system (e.g., computer server power supplies, high-power chargers, TV power supplies), the collaborative workflow between the PFC module and LLC module is as follows:

AC Input → Rectifier Bridge → PFC Module → Stabilized High-Voltage DC (400V) → LLC Module → Isolated Stabilized Low-Voltage DC → Load