Sensorless Current Sharing in Digitally Controlled Two-Phase Buck DC-DC Converters

This paper describes a current sharing technique for digitally controlled two-phase buck DC-DC converters where pulse width and resistance mismatches are digitally compensated to achieve approximately equal current sharing without sensing currents. Effects of various non-idealities on the current sharing performance are discussed and corresponding mitigation techniques are presented. An extension to converters with more than two phases is discussed. Experimental results are shown for a two-phase synchronous buck converter with 6V input voltage, and 1.3 V, 0 - 20 A output.

[1]  Aleksandar Prodic,et al.  High-frequency digital controller IC for DC/DC converters , 2002, APEC. Seventeenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.02CH37335).

[2]  Aleksandar Prodic,et al.  High-frequency digital PWM controller IC for DC-DC converters , 2003 .

[3]  Aleksandar Prodic,et al.  Design and implementation of a digital PWM controller for a high-frequency switching DC-DC power converter , 2001, IECON'01. 27th Annual Conference of the IEEE Industrial Electronics Society (Cat. No.37243).

[4]  S. Huth.  DC/DC-converters in parallel operation with digital load distribution control , 1996, Proceedings of IEEE International Symposium on Industrial Electronics.

[5]  Issa Batarseh,et al.  A multiphase DC/DC converter with hysteretic voltage control and current sharing , 2002, APEC. Seventeenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.02CH37335).

[6]  David J. Perreault,et al.  Frequency-based current-sharing techniques for paralleled power converters , 1996 .

[7]  W.P. Marnane,et al.  Sensorless Current-Sharing in Multiphase Power Converters , 2006, 2006 IEEE Workshops on Computers in Power Electronics.

[8]  P. Midya,et al.  Sensorless current mode control-an observer-based technique for DC-DC converters , 1997, PESC97. Record 28th Annual IEEE Power Electronics Specialists Conference. Formerly Power Conditioning Specialists Conference 1970-71. Power Processing and Electronic Specialists Conference 1972.

[9]  Seth R. Sanders,et al.  Architecture and IC implementation of a digital VRM controller , 2003 .

[10]  Haitao Hu,et al.  Nonlinear Control for Improved Dynamic Response of Digitally Controlled DC-DC Converters , 2006 .

[11]  Fred C. Lee,et al.  A classification and evaluation of paralleling methods for power supply modules , 1999, 30th Annual IEEE Power Electronics Specialists Conference. Record. (Cat. No.99CH36321).

[12]  Qu Wenlong,et al.  Implementation of a current share method for paralleling of DC/DC converter without control interconnection , 2003, Sixth International Conference on Electrical Machines and Systems, 2003. ICEMS 2003..

[13]  Regan Zane,et al.  System Modeling and Digital Control in Modular Masterless Multi-phase DC-DC Converters , 2006 .

[14]  A. Prodic,et al.  Self-tuning digital current estimator for low-power switching converters , 2008, 2008 Twenty-Third Annual IEEE Applied Power Electronics Conference and Exposition.

[15]  V. Yousefzadeh,et al.  Proximate Time-Optimal Digital Control for DC-DC Converters , 2007, 2007 IEEE Power Electronics Specialists Conference.

[16]  Lilly Huang,et al.  Sensorless Current Sharing Analysis and Scheme For Multiphase Converters , 2008 .

[17]  Dragan Maksimovic,et al.  Sensorless optimization of dead times in dc–dc converters with synchronous rectifiers , 2006, IEEE Transactions on Power Electronics.

[18]  D. Perreault,et al.  Frequency-based current-sharing techniques for paralleled power converters , 1996, PESC Record. 27th Annual IEEE Power Electronics Specialists Conference.

[19]  K. Siri,et al.  Analysis and evaluation of current-sharing control for parallel-connected DC-DC converters taking into account cable resistance , 1995, 1995 IEEE Aerospace Applications Conference. Proceedings.

[20]  Zhiqiang Gao,et al.  Distributed, Master-less Control of Modular DC-DC Converters , 2004 .

[21]  F. C. Lee,et al.  Analysis and design of N paralleled DC-DC converters with master-slave current-sharing control , 1997, Proceedings of APEC 97 - Applied Power Electronics Conference.

[22]  V. Yousefzadeh,et al.  Hybrid DPWM with Digital Delay-Locked Loop , 2006, 2006 IEEE Workshops on Computers in Power Electronics.

[23]  J. S. Glaser,et al.  Output plane analysis of load-sharing in multiple-module converter systems , 1994 .