Advanced Control for Very Fast DC-DC Converters Based on Hysteresis of the Current Santa

The bandwidth achievable by using voltage mode control or current mode control in switch-mode power supply is limited by the switching frequency. Fast transient response requires high switching frequency, although lower switching frequencies could be more suitable for higher efficiency. This paper proposes the use of hysteretic control of the output capacitor current to improve the dynamic response of the buck converter. An external voltage loop is required to accurately regulate the output voltage. The design of the hysteretic loop and the voltage loop are presented. Besides, it is presented a non-invasive current sensor that allows measuring the current in the capacitor. This strategy has been applied for DVS (dynamic voltage scaling) on a 5 MHz buck converter. Experimental results validate the proposed control technique and show fast transient response from 1.5 V to 2.5 V in 2 .

[1]  Mario Marchesoni,et al.  Power conditioning system using sliding model control , 1988, PESC '88 Record., 19th Annual IEEE Power Electronics Specialists Conference.

[2]  D. Biel,et al.  Optimum dynamic performance of a buck converter , 1996, 1996 IEEE International Symposium on Circuits and Systems. Circuits and Systems Connecting the World. ISCAS 96.

[3]  R. Redl,et al.  Optimizing the load transient response of the buck converter , 1998, APEC '98 Thirteenth Annual Applied Power Electronics Conference and Exposition.

[4]  G. Schuellein,et al.  Current sharing of redundant synchronous buck regulators powering high performance microprocessors using the V/sup 2/ control method , 1998, APEC '98 Thirteenth Annual Applied Power Electronics Conference and Exposition.

[5]  G. Verghese,et al.  Nonlinear phenomena in power electronics : attractors, bifurcations, chaos, and nonlinear control , 2001 .

[6]  Song Qu,et al.  Modeling and design considerations of V/sup 2/ controlled buck regulator , 2001, APEC 2001. Sixteenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.01CH37181).

[7]  J.A. Cobos,et al.  Analysis of the buck converter for scaling the supply voltage of digital circuits , 2003, Eighteenth Annual IEEE Applied Power Electronics Conference and Exposition, 2003. APEC '03..

[8]  Henry Shu-Hung Chung,et al.  Dynamic hysteresis band control of the buck converter with fast transient response , 2005, IEEE Transactions on Circuits and Systems II: Express Briefs.

[9]  J.A. Cobos,et al.  Design methodology for dynamic voltage scaling in the buck converter , 2005, Twentieth Annual IEEE Applied Power Electronics Conference and Exposition, 2005. APEC 2005..

[10]  E. Olias,et al.  The fast response double buck DC-DC converter (FRDB): operation and output filter influence , 2005, IEEE Transactions on Power Electronics.

[11]  J.A. Cobos,et al.  Nonlinear digital control breaks bandwidth limitations , 2006, Twenty-First Annual IEEE Applied Power Electronics Conference and Exposition, 2006. APEC '06..

[12]  Yan-Fei Liu,et al.  An Optimal Control Method for Buck ConvertersUsing a Practical Capacitor ChargeBalance Technique , 2008, IEEE Transactions on Power Electronics.

[13]  V. Yousefzadeh,et al.  Proximate Time-Optimal Digital Control for Synchronous Buck DC–DC Converters , 2008, IEEE Transactions on Power Electronics.

[14]  Damian Giaouris,et al.  Stability Analysis of the Continuous-Conduction-Mode Buck Converter Via Filippov's Method , 2008, IEEE Transactions on Circuits and Systems I: Regular Papers.

[15]  A. Prodic,et al.  Continuous-Time Digital Controller for High-Frequency DC-DC Converters , 2008, IEEE Transactions on Power Electronics.

[16]  V. Yousefzadeh,et al.  Nonlinear digital PID controller for DC-DC converters , 2008, 2008 Twenty-Third Annual IEEE Applied Power Electronics Conference and Exposition.

[17]  Jian Sun,et al.  Ripple-Based Control of Switching Regulators—An Overview , 2009, IEEE Transactions on Power Electronics.

[18]  L. Corradini,et al.  Digital Hysteretic Voltage-Mode Control for DC–DC Converters Based on Asynchronous Sampling , 2009, IEEE Transactions on Power Electronics.

[19]  O. Garcia,et al.  Design methodology of a non-invasive sensor to measure the current of the output capacitor for a very fast non-linear control , 2009, 2009 Twenty-Fourth Annual IEEE Applied Power Electronics Conference and Exposition.

[20]  Pedro Alou,et al.  Nonlinear Control for DC–DC Converters Based on Hysteresis of the $C_{\rm OUT}$ Current With a Frequency Loop to Operate at Constant Frequency , 2011, IEEE Transactions on Industrial Electronics.

[21]  Sriram Chandrasekaran,et al.  Controller for a power converter and method of operation , 2013 .