AN3180: Ripple-Free Input Current PFC Pre-Regulator with L6563S Application Note

About this manual

The document details a method to reduce differential mode line filter requirements in offline switching converters by utilizing the zero-ripple current phenomenon. It focuses on implementing this technique with the L6563S controller to create a 200 W PFC pre-regulator that minimizes input ripple current.

The note covers theoretical foundations, including coupled inductor models and sensitivity analysis, alongside practical implementation steps such as capacitor selection and magnetic component design. It includes bench results from an EVL6563S-ZRC200 demonstration board to validate the approach against EMI standards.

What's inside

• Basic topologies with zero-ripple current
• Zero-ripple current phenomenon: theory
• Sensitivity of zero-ripple current condition
• Capacitor selection
• 200 W ripple-free input current PFC pre-regulator

Specifications

Frequently asked questions

What is the main limitation of transition-mode-operated PFC pre-regulators?

Their considerable input ripple current, which requires a large differential mode line filter to meet EMI requirements.

What technique helps reduce the need for DM filtering in PFC pre-regulators?

The ripple-steering technique, which can theoretically reduce an inductor ripple current to zero.