Infineon IR1155STRPBF: A High-Performance One-Cycle Control PFC IC for Switching Power Supplies

In the realm of modern power electronics, achieving high efficiency and robust performance in switching power supplies is paramount. The Infineon IR1155STRPBF stands out as a specialized integrated circuit (IC) designed to address these critical demands through its innovative One-Cycle Control (OCC) digital core technology. This Power Factor Correction (PFC) controller is engineered to enhance energy efficiency, reduce total harmonic distortion (THD), and simplify design complexity for a wide range of AC-DC power applications.

Core Technology and Operational Advantages

At the heart of the IR1155STRPBF is its proprietary One-Cycle Control technique, which fundamentally differs from conventional analog or multi-cycle digital methods. This approach allows the IC to precisely regulate the input current on a cycle-by-cycle basis, forcing it to instantly follow the sinusoidal shape of the input voltage. This results in an exceptionally near-unity power factor (PF > 0.99) and very low THD, even under universal input voltage ranges (85 VAC to 265 VAC) and varying load conditions. The OCC method inherently provides rapid response to load and line transients, enhancing system stability and performance without the need for complex compensation networks typically required by traditional multiplier-based PFC controllers.

Key Features and System Benefits

The IR1155STRPBF integrates several features that contribute to its high performance and design flexibility:

Average Current Mode Control: This ensures low electromagnetic interference (EMI) and quieter operation.

Internal Start-Up Timer: It reduces external component count and simplifies the bootstrapping process.

Over-Voltage Protection (OVP) and Brown-Out Detection: These built-in safeguards enhance system reliability and protect against fault conditions.

Frequency Modulation: A small amount of frequency jitter is introduced to spread the EMI spectrum, simplifying filter design and helping to meet stringent regulatory standards.

By integrating these functionalities, the IC enables designers to create compact, high-efficiency power supplies that comply with international energy standards like ENERGY STAR and EU CoC. Its 8-pin SOIC package makes it suitable for space-constrained applications, including server and telecom power systems, industrial motor drives, and high-brightness LED lighting.

Design Simplification and Efficiency

A significant advantage of the One-Cycle Control method is its ability to eliminate the traditional analog multiplier and the input voltage sensing network. This drastic reduction in external components not only lowers the overall bill of materials (BOM) and board space but also improves system reliability. Furthermore, the IR1155STRPBF operates at a fixed frequency in Continuous Conduction Mode (CCM), which is ideal for higher-power applications (typically above 300W) and contributes to higher overall efficiency across the entire load range.

ICGOODFIND Summary

The Infineon IR1155STRPBF is a superior PFC controller that leverages its unique One-Cycle Control digital core to deliver outstanding performance. It masterfully combines exceptional power factor correction, low total harmonic distortion, and fast dynamic response with a significantly simplified design process. For engineers developing high-performance AC-DC power supplies, this IC represents an optimal solution to achieve higher efficiency, greater reliability, and reduced time-to-market.

Keywords: Power Factor Correction (PFC), One-Cycle Control (OCC), Total Harmonic Distortion (THD), Switching Power Supplies, High Efficiency