Infineon Technologies SMPS Design Center
Infineon Technologies SMPS Design Center provides engineers insight into various topologies used in SMPS designs. The wide array of design notes covers topics that include CrCM flyback PFC converters, CrCM and CCM PFC boost converters, offline fixed frequency DCM flyback converters, QR flyback converters, phase shifted full-bridge converters, forward converters, LLC converters, and buck converters.
CrCM Flyback PFC
Power factor correction (PFC) shapes the input current of the power supply to be in synchronization with the mains voltage in order to maximize the real power drawn from the mains. This document is intended to discuss the topology and operational mode for low-power (<100W) PFC applications.
CrCM Flyback PFC Converter Design Notes
CCM / CrCM PFC Boost
Infineon PFC boost critical conduction mode (CrCM) / continuous conduction mode (CCM) helps shape the input current of the power supply to be in synchronization with the mains voltage, in order to maximize the real power drawn from the mains. CCM is the most popular topology used in PFC applications and is commonly used for medium/high power ranges (higher than 300W). CrCM is more commonly used for low power (less than 300W) PFC applications.
CCM PFC Boost Converter Design Notes
CrCM PFC Boost Converter Design Notes
Offline Fixed Frequency DCM Flyback
For low current output and power level below 50W, discontinuous conduction mode (DCM) flyback is the popular operating mode. The design note helps to develop a comprehensive and easy-to-follow approach to designing an offline DCM flyback power supply.
Off-line Fixed Frequency DCM Flyback Converter Design Notes
QR Flyback
A quasi-resonant (QR) flyback is simply a DCM flyback having a valley switching turn on. It is largely used in low-power SMPS applications such as chargers, adapters, and auxiliary supplies. The objective of this paper is to develop a practical, step-by-step approach to designing an offline QR flyback power supply.
QR Flyback Converter Design Notes
Forward
The single transistor forward converter is commonly used for offline supplies in a power range below 200W. This document aims to discuss the single-ended forward topology in detail and point out some key differences to flyback topology.
Forward Converter Design Notes
LLC
LLC topology has been used sparingly in high-end applications that require the highest efficiency possible. Use LLC in offline SMPS with a pre-regulated bus (PFC) when efficiency and power density are the highest priorities.
LLC Converter Design Note
Phase Shifted Full-Bridge
In AC/DC rectifiers, while the front-end stage achieves PFC and regulates the bus voltage to a DC value (~390V), the DC-DC stage must step down the bus voltage and provide a galvanically isolated and tightly regulated DC output (12V, 24V, 48V). This document is intended to discuss the topology and operation of the DC-DC stage for high-power ( >400W) applications and provide detailed design equations with examples.
Phase Shifted Full-Bridge Converter with Current Doubler Rectifier Design Notes
Buck
A buck converter is the most basic SMPS topology. The buck converter (voltage step-down converter) is a non-isolated converter, meaning galvanic isolation between input and output is not given. The buck converter is the most popular topology used to distribute power in complex systems, such as server motherboards, broadband communication boards, etc. It provides the required local voltage from a higher voltage bus that is common to multiple converters in the system. The converter itself consists of one active switch controlled by an IC, a rectifier, and filter elements. This great simplicity allows for cost-effective, highly efficient power distribution throughout the application.
Buck Converter Design Notes