Designing a High-Voltage SMPS with the Infineon PEB4266VV2 PFC and Quasi-Resonant Controller IC

The demand for high-efficiency, high-power-density Switch-Mode Power Supplies (SMPS) continues to grow across industries such as computing, telecommunications, and consumer electronics. Meeting stringent energy efficiency regulations like ErP and 80 PLUS Titanium requires advanced topologies that minimize losses. A two-stage approach, combining a Power Factor Correction (PFC) front-end with a highly efficient DC-DC conversion stage, has become the standard for high-performance power supplies above 300W. The Infineon PEB4266VV2 is a highly integrated controller that combines both a critical conduction mode (CrM) PFC controller and a quasi-resonant (QR) current-mode PWM controller in a single package, simplifying the design of such high-voltage SMPS.

The first critical stage in an AC-DC power supply is Power Factor Correction. The PFC stage's role is to shape the input current to be sinusoidal and in phase with the input voltage, maximizing the real power drawn from the mains and reducing harmonic distortion. The PEB4266VV2 employs a Critical Conduction Mode (CrM) / Transition Mode (TM) control scheme for the PFC. This mode ensures the boost inductor current operates at the boundary between continuous and discontinuous conduction. The key advantage is that the boost MOSFET is turned on at valley switch condition (when the inductor current reaches zero), significantly reducing turn-on losses compared to a fixed-frequency hard-switching topology. This leads to higher efficiency, especially at high line voltages, and minimizes electromagnetic interference (EMI).

Following the PFC stage, which provides a stable ~400V DC bus, the second stage converts this high voltage to the required isolated low-voltage output. The PEB4266VV2 integrates a controller for this stage based on the Quasi-Resonant (QR) Flyback topology. QR operation is a significant advancement over conventional flyback converters. It works by detecting the valley of the drain-source voltage waveform on the primary-side MOSFET after the core has reset. By enabling the MOSFET to turn on at this minimum voltage point (valley switching), the controller achieves Zero-Voltage Switching (ZVS). This dramatically reduces switching losses, audible noise, and EMI, making the QR flyback one of the most popular topologies for medium-power applications.

Designing with the PEB4266VV2 offers several key benefits due to its high level of integration. The IC provides comprehensive protection features including over-voltage protection (OVP), over-current protection (OCP), brown-out protection, and over-temperature protection for both stages, enhancing system reliability. Furthermore, the controller implements an innovative dynamic response management (DRM) circuit for the QR stage. This feature improves the load transient response, which is a traditional weakness of quasi-resonant controllers, ensuring stable output voltage under rapidly changing load conditions.

A successful design hinges on careful component selection and layout. The choice of the boost inductor for the PFC and the flyback transformer for the QR stage is paramount. These components must be designed for the specific power level and optimized for low core and winding losses. The PCB layout must prioritize minimizing high-frequency switching loops to reduce parasitic inductance and EMI. Proper grounding and shielding are essential to ensure stable operation of the sensitive controller circuitry.

ICGOODFIND: The Infineon PEB4266VV2 is a powerful and highly integrated solution for designers aiming to build compact, high-efficiency, and reliable high-voltage SMPS. By merging a high-performance CrM PFC controller with an advanced Quasi-Resonant flyback controller, it simplifies the two-stage architecture, reduces component count, and delivers the performance necessary to meet the most demanding global energy efficiency standards.

Keywords:

1. Quasi-Resonant Controller

2. Power Factor Correction (PFC)

3. Valley Switching

4. Critical Conduction Mode (CrM)

5. Zero-Voltage Switching (ZVS)