Essential-coupling-path models for non-contact EMI in switching power converters using lumped circuit elements

Author name used in this publication: Chi K. TseAuthor name used in this publication: C. P. Liu2002-2003 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

A novel high frequency current-driven synchronous rectifier applicable to most switching topologies

A novel current-driven synchronous rectifier is presented in this paper. With the help of current sensing energy recovery circuit, the proposed current-driven synchronous rectifier can operate at high switching frequency with high efficiency. Compared with those voltage-driven synchronous rectification solutions, this current-driven synchronous rectifier has several outstanding characteristics. It can be easily applied to most switching topologies like an ideal diode. Constant gate drive voltage can be obtained regardless of line and load fluctuation. This makes it desirable in high input range application. Converters designed with this synchronous rectifier are also capable of being connected in parallel without taking the risk of reverse power sinking. Principle of operation is given in the paper. A series of experiments verify the analysis and demonstrate the merits.published_or_final_versio

Common-Mode Noise Cancellation in Switching-Mode Power Supplies Using an Equipotential Transformer Modeling Technique

Electromagnetic interference (EMI) is a significant challenge in the design of high-efficiency switching-mode power supplies due to the presence of common-mode (CM) noise. In many power-supply designs, a variety of noise suppression schemes must be implemented in order to meet EMI requirements. Most of these schemes create power loss that lead to efficiency and thermal issues. In this paper, a transformer construction technique is proposed that effectively reduces the CM noise current injecting across the isolated primary and secondary windings. This technique is based on the zero equipotential line theory. A transformer design with the proposed CM noise cancellation technique can achieve high conversion efficiency as well as substantial CM noise rejection.published_or_final_versio

Low output ripple DC-DC converter based on an overlapping dual asymmetric half-bridge topology

A new converter topology is described for applications requiring very low output current ripple. The proposed converter consists of two asymmetric half-bridge converters whose output voltages overlap in a finite interval of time. This converter provides well regulated and smooth dc output without the need of an output filter. The output voltage is regulated by direct amplitude modulation. Unlike the standard interleaved converters, the proposed converter is robust to input voltage and operating duty cycle variations. Furthermore, equal current sharing is automatically achieved under all conditions, thus ensuring full utilisation of the output rectifiers for wide input and output ranges. The circuit achieves zero-voltage turnon for all primary switches and zero-current turnoff for the output rectifiers. An isolated dc-dc converter prototype with 5-V output voltage and 20-A output current has been built to verify the design. © 2007 IEEE.published_or_final_versio

Practical solutions to the design of current-driven synchronous rectifier with energy recovery from current sensing

Current-driven synchronous rectifier with current sensing energy recovery has been proved to be suitable for almost all high frequency switching topologies. The synchronous rectifier can be driven on and off automatically according to the current direction. In fact it can be taken as an active diode with very low power dissipation. Some theoretical analysis and experimental results have been shown in the previous work. This paper presents an extended analysis to some practical considerations when applying this current-driven synchronous rectifier in switching converter design.published_or_final_versio

Techniques for input ripple current cancellation : classification and implementation

Author name used in this publication: J. C. P. LiuAuthor name used in this publication: C. K. TseAuthor name used in this publication: M. H. Pong2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Low output ripple DC-DC converter based on an overlapping dual asymmetric half-bridge topology

Author name used in this publication: Chi K. Tse2007-2008 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

A knowledge model-based BIM framework for automatic code-compliant quantity take-off

The results of quantity take-off (QTO) based on building information modeling (BIM) technology rely heavily on the geometry and semantics of 3D objects that may vary among BIM model creation methods. Furthermore, conventional BIM models do not contain all the required information for automatic QTO and the results do not follow the descriptive rules in the standard method of measurement (SMM). This paper presents a new knowledge model-based framework that incorporates the semantic information and SMM rules in BIM for automatic code-compliant QTO. It begins with domain knowledge modeling, taking into consideration QTO-related information, semantic QTO entities and relationships, and SMM logic formulation. Subsequently, linguistic-based approaches are developed to automatically audit the BIM model integrity for QTO purposes, with QTO algorithms developed and used in a case study for demonstration. The results indicate that the proposed new framework automatically identifies the semantic errors in BIM models and obtains code-compliant quantities

A single phase voltage regulator module (VRM) with stepping inductance for fast transient response

A single-phase fast transient converter topology with stepping inductance is proposed. The stepping inductance method is implemented by replacing the conventional inductor in a buck converter by two inductors connecting in series. One has large inductance and the other has small inductance. The inductor with small inductance will take over the output inductor during transient load change and speed up dynamic response. In steady state, the large inductance takes over and keeps a substantially small ripple current and minimizes root mean square loss. It is a low cost method applicable to converters with an output inductor. A hardware prototype of a 1.5-V dc-dc buck converter put under a 100-A transient load change has been experimented upon to demonstrate the merit of this approach. It also serves as a voltage regulator module and powers up a modern PC computer system. © 2007 IEEE.published_or_final_versio

Comparison of three topologies for VRM fast transient application

This paper compares three topologies for voltage regulator module VRM for fast transient application. The topologies are the most popular multi-phase converter, a synchronous rectifier buck converter topology and a recently introduced new stepping inductor converter. Analysis and simulation show that the stepping inductor topology gives the fastest response with minimal amount of output filter capacitance.published_or_final_versio