Fairchild FAN6204 Synchronous Rectification Controller Application Note

About this manual

The document introduces the Fairchild FAN6204, a synchronous rectification (SR) controller designed for continuous and discontinuous conduction mode flyback converters and dual-switch forward free-wheeling rectification. It highlights the use of proprietary linear-predict timing control to determine SR MOSFET turn-on and turn-off timing by detecting transformer winding and output voltage, which enhances noise immunity and simplifies PCB layout by eliminating the need for primary-side communication signals. The note also covers various protection functions, including Fault Causal Timing, Gate Expand Limit, and Over-Temperature Protection, as well as a Green Mode for light-load efficiency.

What's inside

• Introduction
• External Components Design
• Flyback Rectification Application
• Dual-Switch Forward Free-Wheeling Rectification Application
• Consideration of External Component Value
• VDD Section
• Printed Circuit Board Layout
• Design Example
• Test Waveforms

Specifications

Frequently asked questions

What control technique does the FAN6204 use?

It utilizes a proprietary innovative linear-predict timing control to determine the turn-on and turn-off timing of SR MOSFET.

Does the FAN6204 require a communication signal from the primary side?

No, this technique doesn't need a communication signal from the primary side, which reduces external components and simplifies PCB layout.