A new driving scheme for synchronous rectifiers: single winding self-driven synchronous rectification

Abstract

Single winding self-driven synchronous rectification (SWSDSR) approach is a new driving circuit that overcomes the limitations of the traditional driving schemes, becoming an interesting alternative to supply new electronic loads as microprocessors. Traditional self-driven synchronous rectification (SDSR) technique has shown very good performance to improve efficiency and thermal management in low-voltage low-power dc/dc converters, however it can not be extended to the new fast dynamic, very low voltage applications. SWSDSR scheme is based on an additional winding in the power transformer (auxiliary winding). It allows for maintaining the synchronous rectifiers (SRs) on even when the voltage in the transformer is zero, which is impossible to do in traditional self-driven approaches. It also makes possible to drive properly the SRs even in very low voltage applications, 1.5 V or less. Coupling of the windings strongly affects the performance of the SWSDSR technique. The influence of the coupling between the different windings is analyzed through simulations of different transformers designed for the same application. Models of transformers are generated with a finite element analysis (FEA) tool. Goodness of the SWSDSR scheme is validated through experimental results.

High Efficiency Design Considerations for the Self-Driven Synchronous Rectified Phase-Shifted Full-Bridge Converters of Server Power Systems

“…In these studies, cost and the complexity of the driver circuit is high due to the additional circuit components. The voltage driven method uses the power transformer directly or the auxiliary winding is used to generate driving signals which in turn results in a cheap and simple solution [17], [20]. In [20], a method using the auxiliary winding to drive the SRs was proposed.…”

A Driving Scheme Using a Single Control Signal for a ZVT Voltage Driven Synchronous Buck Converter

“…2(b), utilizes the voltage across the output inductor or the secondary side of the transformer to drive the SR [7]- [14]. This converter is non-isolated and does not have a transformer.…”

Optimization of a self-driven current-doubler phase shifted full bridge DC-DC converter with integrated magnetic

“…Leakage inductance of auxiliary winding should be as small as possible to get reliable and quality driving signal. Therefore, auxiliary windings are placed between the primary and the secondary windings in each outer leg of the transformer (Alou et al, 2001).…”