Short Topics in the Application of Power Factor Controllers

摘要

Designing power factor correction (PFC) into modern switched-mode power supplies has changed over the past few years due to the introduction of many new controller ICs. Today, it is possible to design a variety of PFC circuits with different modes of operation, each with its own set of challenges. As the number of choices has increased, so has the complexity of making the choice and then executing the design. This paper briefly reviews the most popular approaches, and then addresses some of the details of the very popular and yet perhaps the most complex approach---the continuous conduction mode. This approach is well suited for power levels in the 150 W to 1 kW power range, and is therefore used by a large number of power supply designers. Different IC controllers have different features and idiosyncrasies. There are virtually no two that are alike enough to be "drop-in replacements" for one another. Therefore, the designer must understand the different features in order to pick the optimum one for the application, and then be prepared to handle the issues of the chosen device. This will not be a chip-by-chip comparison, but rather a general discussion, and then a specific example based on the latest (and somewhat different) PFC IC from ON Semiconductor.