Proceedings ArticleDOI
Practical application of MOSFET synchronous rectifiers
J. Blanc
- pp 495-501
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TLDR
In this paper, the theoretical minimum losses of synchronous rectifiers for a forward power converter with resonant reset were analyzed under the assumption of ideal gate-drive waveforms. But the analysis showed that the gate charge and on-resistance of the current generation of power MOSFETs are low enough to yield a significant increase in rectifier efficiency, and the effects of parasitic circuit inductances on the gate voltage waveforms were shown.Abstract:
The application of MOSFET synchronous rectifiers (SRs) to a forward power converter with resonant reset is analyzed. Under the assumptions of ideal gate-drive waveforms, the theoretical minimum losses are determined. The analysis shows that the gate charge and on-resistance of the current generation of power MOSFETs are low enough to yield a significant increase in rectifier efficiency. Two simple gate drive circuits are presented, and the effects of parasitic circuit inductances on the gate voltage waveforms are shown. The measured converter losses for these SR drive circuits are compared to the losses for the Schottky rectifiers, as well as to the theoretical minimum losses. For the 3.3 V output at load currents between 5 and 10 A, the losses approach the theoretical minimum. For higher load currents, the MOSFET body-drain diode causes losses during its reverse recovery, due to the nonideal timing of gate drive voltages. >read more
Citations
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Journal ArticleDOI
Silicon carbide benefits and advantages for power electronics circuits and systems
Ahmed Elasser,T.P. Chow +1 more
TL;DR: The benefits of using SiC in power electronics applications are looked at, the current state of the art of SiC is reviewed, and how SiC can be a strong and viable candidate for future power electronics and systems applications are shown.
Patent
High efficiency power converter
TL;DR: In this article, a power converter nearly losslessly delivers energy and recovers energy from capacitors associated with controlled rectifiers in a secondary winding circuit, each controlled rectifier having a parallel uncontrolled rectifier.
Patent
Low loss synchronous rectifier for application to clamped-mode power converters
TL;DR: In this paper, a synchronous rectifier for use with a clamped-mode power converter uses in one embodiment a hybrid rectifier with a MOSFET rectifying device active in one first cyclic interval of the conduction/nonconduction sequence of the power switch and a second rectifier embodied in one illustrative embodiment as a low voltage bipolar diode rectifier active during an alternative interval to the first conduction and nonconduction interval.
Journal ArticleDOI
Evaluation of synchronous-rectification efficiency improvement limits in forward converters
TL;DR: Estimates of the upper limits of the efficiency improvements of the discussed synchronous rectification approaches relative to the Schottky diode implementation are derived and experimental comparisons of efficiencies for an offline, 3.3 V/20 A forward power converter power stage are presented and compared with theoretically estimated ones.
Patent
Self-synchronized drive circuit for a synchronous rectifier in a clamped-mode power converter
Wayne C. Bowman,Van A. Niemela +1 more
TL;DR: In this paper, the polarities of these windings are selected so that the switched devices are driven appropriately to rectify the periodic signal output of the secondary winding of the power transformer of the converter.
References
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Proceedings ArticleDOI
A MOSFET resonant synchronous rectifier for high-frequency DC/DC converters
W.A. Tabisz,F.C. Lee,Dan Chen +2 more
TL;DR: In this paper, a resonant synchronous rectifier which combines the fast switching of Schottky diodes with low conduction drop of MOSFET devices is discussed.
Proceedings ArticleDOI
Performance of low loss synchronous rectifiers in a series-parallel resonant DC-DC converter
Rayette Ann Fisher,Charles Steven Korman,G.A. Franz,G.W. Ludwig,J.P. Walden,Sayed-Amr Ahmes El-Hamamsy,Krishna Shenai,M.H. Kuo +7 more
TL;DR: In this article, the functionality of efficient synchronous rectifier components, specially developed for resonant DC-DC converter topologies designed to operate at high frequency, has been demonstrated in a series-parallel converter circuit operating at 420 kHz and 85 W.
Proceedings ArticleDOI
Analysis of a resonant reset condition for a single-ended forward converter
N. Murakami,M. Yamasaki +1 more
TL;DR: In this article, the authors analyzed the reset condition of a transformer core flux for a single-ended forward converter operating in a resonant reset mode and derived the relationship between reset time and device parameters such as the main switch output capacitance.
Proceedings ArticleDOI
Worth of a Watt - Implications for Systems and Device Designers
TL;DR: In this article, the capital equivalent cost of consuming ac or dc power in a central office is determined as a function of service life, electric rate and energy inflation rate, and the results are used to compute life-cycle equipment costs and to determine the most economical operating point of nonlinear power processing devices.
Proceedings ArticleDOI
Worth of a watt for power systems in digital loop carrier and other remote locations
TL;DR: The worth of a watt concept deals with the cumulative operating expense associated with consuming one AC watt of power at any point in a central office power processing chain this article, and it has been extended to power systems in "confined locations" (e.g., small above-ground or below-ground enclosures, that house loop and interoffice electronic equipment).