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研究生: 林詩梅
Lin, Shih-Mei
論文名稱: 具快速響應之電流模式及遲滯定頻降壓型轉換器
Fast-Response Buck Converters with Current-Mode and Fixed-Frequency Hysteretic Control
指導教授: 蔡建泓
Tsai, Chien-Hung
學位類別: 碩士
Master
系所名稱: 電機資訊學院 - 電機工程學系
Department of Electrical Engineering
論文出版年: 2014
畢業學年度: 102
語文別: 英文
論文頁數: 141
中文關鍵詞: 切換是穩壓器漣波控制遲滯控制電流模式控制定頻快速暫態響應
外文關鍵詞: Switching Regulators, Ripple-based Control, Hysteretic Control, Current-Mode Control, Fixed-Frequency, Fast-Transient
相關次數: 點閱:167下載:18
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  • 本論文之研究目標為定頻之快速暫態響應穩壓器。依據控制方式可分為兩部分:
    第一部為快速暫態響應之電流模式控制切換式降壓轉換器,藉由系統的設計與流程,包含系統模型、補償器設計、電晶體層次設計、晶片下線,將電流模式穩壓器的迴路特性優化,以達到較好的暫態響應。量測結果證明在輸入電壓於2.7~4.2V的鋰電池供電範圍內,在200mA~500mA負載電流範圍內,此轉換器可以穩定的提供1.8V的輸出電壓,暫態響應最快只需10us,最高轉換效率為93%。而藉由頻域的量測,也證明了本設計與分析流程的正確性,同時證明系統的穩定性。本電流模式控制降壓轉換器使用TSMC 0.35μm CMOS製程進行設計,外接電感與輸出電容分別為4.7μH與10uF。
    本論文第二部分提出一具有快速暫態響應、寬負載電流範圍、近似V2之定頻遲滯控制切換式降壓穩壓器。此穩壓器使用鎖相迴路,藉由所提出之二級視窗控制電路來改善非線性控制不定頻的缺點,使其在重載時系統可以定頻操作。在極輕載時為維持轉換效率,本系統可自動進入PFM模式操作。本論文使用的近似V2之架構,可以不需要依靠輸出電容ESR即可取得與電感電流同相之訊號,可使用小ESR的電容降低輸出漣波。本轉換器使用TSMC 0.35μm CMOS製程進行設計與製作,外接電感與輸出電容分別為2.2μH與10μF,量測結果顯示在輸入電壓3.3V~3.9V、負載電流為18mA~700mA的範圍內,可以提供穩定之輸出電壓1.2V,暫態響應小於5us,最高轉換效率為95.6%。

    This thesis is about the fixed-frequency fast-transient regulator. Based on control methods, the thesis can be divided into two parts:
    The first part focuses on the fast transient current-mode controlled buck converter. Through the systematic design procedure and analysis including the system modeling, compensator design, transistor level design, and chip implementation, the loop response is improved for better dynamic response. The design procedure is verified by the chip’s measurement results. The measurement results show that this converter can operate with load current from 200mA to 500mA in a supply voltage from 2.7 to 4.2V and the output voltage of 1.8V. The recovery time is about 10us and the highest efficiency is 93%. By the frequency domain measurement, the stability of proposed buck converter can be guaranteed. This converter is designed and fabricated with TSMC 2P4M 0.35μm CMOS process. The off chip inductor and the output capacitor are 4.7μH and 10μF.
    In the second part of this thesis, a fast transient quasi-V2 fixed-frequency hysteretic buck converter with wide load current range is proposed. This converter uses the phase-locked loop through the proposed Two Stage Window Control Circuit to stabilize the switching frequency. Under ultra-light load condition, this converter operates in PFM mode to reduce the switching loss and improve the light load efficiency. By the quasi-V2 technique, the inductor current information can be obtained without relying on large ESR of output capacitor to reduce the output ripple. This converter has been designed and fabricated by TSMC 2P4M 0.35μm CMOS process. The off chip inductor and the output capacitor are 2.2μH and 10uF. The measurement results show that this converter can operate with load current from 18mA-700mA in a supply voltage from 3.3-3.9V, and the output voltage of 1.2V. With the PLL, the switching frequency is maintained constant at 1MHz. The transient response time is about 5us and the highest efficiency is 95.6%.

    口試委員會審定書 ii 中文摘要 iv ABSTRACT v 致謝 vii CONTENTS viii LIST OF FIGURES xiii LIST OF TABLES xviii Chapter 1 Introduction 1 1.1 Background and Motivation 1 1.2 Challenges and Objectives 3 1.3 Thesis Organization 4 Chapter 2 Current-Mode Buck Converter Fundamentals 6 2.1 Operation Principle 6 2.1.1 PWM Operation 6 2.1.2 PFM Operation 9 2.2 Small Signal Model and Analysis 10 2.2.1 Current Loop 11 2.2.2 Voltage Loop 15 2.3 Compensation Techniques 18 2.3.1 Off-Chip Compensation 19 2.3.2 On-Chip Compensation 21 2.3.3 Adaptive Compensation 22 2.4 Related Research Topics 23 2.4.1 Current Sensor 24 2.4.2 High Efficiency 25 2.4.3 Fast Transient Response 26 2.4.4 Others 28 Chapter 3 Ripple-Based Buck Converter Fundamentals 29 3.1 Operation Principle 29 3.2 Ripple-Based Control Classification 31 3.2.1 Voltage-Mode Hysteretic Control 32 3.2.2 Current-Mode Hysteretic Control 37 3.2.3 Constant On-time Control 38 3.2.4 V2 Control 41 3.2.5 Comparison and Discussion 46 3.3 Problems and Solutions 47 3.3.1 Large ESR Requirement 47 3.3.2 Regulation Enhancement 51 3.3.3 Switching Frequency Variation 52 Chapter 4 Ripple-Based Buck Converters with Switching Frequency Stabilization Capability 53 4.1 Quasi-fixed Frequency Constant On-time Buck Converter 53 4.1.1 Input/Output Voltage Independent 55 4.1.2 Load Current Independent 57 4.1.3 Recent Research Review 59 4.2 Fixed Frequency Hysteretic Buck Converter 62 4.2.1 Hysteretic Window Adjustment 63 4.2.2 Loop Delay Adjustment 65 4.2.3 Recent Research Review 66 4.3 Fundamentals of PLL [76] 72 4.3.1 Operation Principle 72 4.3.2 Analysis and System Modelling 73 Chapter 5 Fast Transient Current-Mode DC-DC Converter with Improved Loop Response 77 5.1 Introduction 77 5.2 System Architecture and Proposed Techniques 78 5.2.1 Methodology for Improved Loop Response 79 5.2.2 Compensator Design 80 5.2.3 Specifications and Verification 82 5.3 Circuit Design 84 5.3.1 OTA 84 5.3.2 Current Sensor 84 5.3.3 Oscillator 85 5.3.4 SUM 86 5.3.5 Comparator 86 5.3.6 Drivers 87 5.3.7 Power MOS transistor 88 5.3.8 Soft-start 88 5.4 Implementation and Measurement Considerations 89 5.4.1 IC Layout and PCB Design 89 5.4.2 Measurement Setup and Test Plan 91 5.5 Experimental Results 91 5.5.1 Steady-state Measurement 91 5.5.2 Transient Response Measurement 92 5.5.3 Efficiency Measurement 93 5.5.4 Loop Response Measurement 93 5.6 Comparison and Discussion 94 5.7 Summary 96 Chapter 6 Fixed Frequency Quasi-V2 Hysteretic Buck Converter with PLL-Based Control 97 6.1 Introduction 97 6.2 Research Overview 98 6.2.1 Hysteretic Buck 98 6.2.2 Fixed-Frequency Hysteretic Buck 99 6.2.3 Conventional V2 Buck 101 6.2.4 Quasi-V2 Hysteretic Buck 102 6.3 System Architecture and Proposed Techniques 103 6.3.1 Control Loop Analysis 105 6.3.2 Phase Locked Loop Design 107 6.3.3 Specifications and Verification 108 6.4 Circuit Design 110 6.4.1 Two Stage Window Control Circuit 110 6.4.2 Compensator 111 6.4.3 Phase Frequency Detector 112 6.4.4 Charge Pump and Low Pass Filter 114 6.4.5 Mode Selector 116 6.5 Implementation and Measurement Considerations 116 6.5.1 IC Layout and PCB Design. 116 6.5.2 Measurement Setup and Test Plan 119 6.6 Experimental Results 120 6.6.1 Steady-state Measurement 120 6.6.2 Transient Response Measurement 122 6.6.3 Efficiency Measurement 124 6.6.4 Frequency Measurement 124 6.7 Comparison and Discussion 126 6.8 Summary 128 Chapter 7 Conclusions 129 7.1 Thesis Summary and Contribution 129 7.2 Future Work 130 REFERENCE 132

    [1] Y. Choi, N. Chang, and T. Kim, "DC-DC Converter-Aware Power Management for Low-Power Embedded Systems," IEEE Trans. Comput.-Aided Des. Integr. Circuits Syst., vol. 26, no. 8, pp. 1367-1381, Aug. 2007.
    [2] C. F. Lee and P. K. T. Mok, "A monolithic current-mode CMOS DC-DC converter with on-chip current-sensing technique," IEEE J. Solid-State Circuits, vol. 39, no. 1, pp. 3-14, Jan. 2004.
    [3] C. H. Chang and R. C. Chang, "A novel current sensing circuit for a current-mode control CMOS DC-DC buck converter," in Proc. IEEE Int. Symp. VLSI Design, Automation and Test, 2005, pp. 120-123.
    [4] R. Jeongjin, "High-performance error amplifier for fast transient DC-DC converters," IEEE Trans. Circuits Syst. II, Exp. Briefs, vol. 52, no. 9, pp. 591-595, Sep. 2005.
    [5] H.-W. Huang, K.-H. Chen, S.-Y. Kuo, “Dithering Skip Modulation, Width and Dead Time Controllers in Highly Efficient DC-DC Converters for System-On-Chip Applications” IEEE J. Solid State Circuits, vol.42, no. 11, pp. 2451-2465, Nov. 2007.
    [6] F.-F. Ma, W.-Z. Chen, and J.-C. Wu, "A Monolithic Current-Mode Buck Converter With Advanced Control and Protection Circuits," IEEE Trans. Power Electron., vol. 22, no. 5, pp. 1836-1846, Sep. 2007.
    [7] K.-H. Chen, C.-J. Chang, and T.-H. Liu, "Bidirectional Current-Mode Capacitor Multipliers for On-Chip Compensation," IEEE Trans. Power Electron, vol. 23, no. 1, pp. 180-188, Jan. 2008.
    [8] W.-R. Liou, M.-L. Yeh, and Y. L. Kuo, "A High Efficiency Dual-Mode Buck Converter IC For Portable Applications," IEEE Trans. Power Electron., vol. 23, no. 2, pp. 667-677, Mar. 2008.
    [9] Y.-H. Lee, Y.-Y. Yang, K.-H. Chen, Y.-H. Lin, S.-J. Wang, K.-L. Zheng, et al., "A DVS Embedded Power Management for High Efficiency Integrated SoC in UWB System," IEEE J. Solid-State Circuits, vol. 45, no. 11, pp. 2227-2238, Nov. 2010.
    [10] J.-C. Tsai, T.-Y. Huang, W.-W. Lai, and K.-H. Chen, "Dual Modulation Technique for High Efficiency in High-Switching Buck Converters Over a Wide Load Range," IEEE Trans. Circuits Syst. I, Reg. Papers, vol. 58, no. 58, pp. 1671-1680, Jul. 2011.
    [11] C.-S. Huang, C.-H. Tsai and J.-H. Wang, "Design and Verification of an Integrated Current-Mode Switching Regulator" IEEE Int. Symp. VLSI Design, Automation and Test, 2011, pp.362-365
    [12] Y.-H. Lee, K.-Y. Chu, C.-J. Shih, and K.-H. Chen, "Proportional Compensated Buck Converter With a Differential-In Differential-Out (DIDO) Error Amplifier and Load Regulation Enhancement (LRE) Mechanism," IEEE Trans. Power Electron., vol. 27, no. 5, pp. 2426-2436, May 2012.
    [13] Y.-H. Lee, S.-C. Huang, S.-W. Wang, and K.-H. Chen, "Fast Transient (FT) Technique With Adaptive Phase Margin (APM) for Current-Mode DC-DC Buck Converters," IEEE Trans. Very Large Scale Integr. (VLSI) Syst., vol. 20, no. 10, pp. 1781-1793, Oct. 2012.
    [14] C.-J. Shih, H.-Y. Chu, Y.-H. Lee, et al., “A Power Cloud System (PCS) for High Efficiency and Enhanced Transient Response in SoC”, IEEE Trans. Power Electron., vol. 28, no. 3, pp. 1320-1330, Mar. 2013
    [15] Linear Technology, “250mA Current-Mode Step-Down DC/DC Converter in Thin SOT”, LTC1779 datasheet, 2000
    [16] Richtech, “1.25MHz, 400mA, High Efficiency PWM Step-Down DC/DC Converter” RT8025 datasheet, 2011
    [17] Texas Instrument, “HIGH-EFFICIENCY STEP-DOWN LOW POWER DC-DC CONVERTER” TPS62000 datasheet, Sep. 2000 [Revised Aug. 2008].
    [18] Robert W. Erickson and Dragan Maksimovic, “Fundamentals of Power Electronics, 2nd ed.”, Norwell, MA: Kluwer Academic Publishers, 2001.
    [19] R. Redl and J. Sun, "Ripple-Based Control of Switching Regulator - An Overview," IEEE Trans. Power Electron., vol. 24, no. 12, pp. 2669-2680, Dec. 2009.
    [20] R. Redl and G. Reizik, "Switched-noise filter for the buck converter using the output ripple as the PWM ramp," in Proc. IEEE Appl. Power Electron. Conf., 2005, pp. 918-924.
    [21] Maxim, “ MAX8640Y/MAX8640Z Data Sheet: Tiny 500mA, 4MHz/2MHz Synchronous Step-Down DC-DC Converters,“ Rev. 3, June 2008, Accessed on Dec. 3, 2008
    [22] F. Su, W. H. Ki, and C. Y. Tsui, "Ultra Fast Fixed-Frequency Hysteretic Buck Converter With Maximum Charging Current Control and Adaptive Delay Compensation for DVS Applications," IEEE J. Solid-State Circuits, vol. 43, no. 4, pp. 815-822, Apr. 2008.
    [23] H. H. Huang, C. L. Chen, and K. H. Chen, "Adaptive Window Control (AWC) Technique for Hysteresis DC-DC Buck Converters With Improved Light and Heavy Load Performance," IEEE Trans. Power Electron., vol. 24, no. 6, pp. 1607-1617, Jun. 2009.
    [24] F. Su and W. H. Ki, "Digitally Assisted Quasi-V2 Hysteretic Buck Converter With Fixed Frequency and Without Using Large-ESR Capacitor," in Proc. IEEE Int. Solid-State Circuits Conf., 2009, pp. 446-447,447a.
    [25] P. Li, D. Bhatia, X. Lin, and R. Bashirullah, "A 90-240 MHz Hysteretic Controlled DC-DC Buck Converter With Digital Phase Locked Loop Synchronization," IEEE J. Solid-State Circuits, vol. 46, no. 9, pp. 2108-2119, Sep. 2011.
    [26] Z. Chen and M. Dongsheng, "A 10-MHz Green-Mode Automatic Reconfigurable Switching Converter for DVS-Enabled VLSI Systems," IEEE J. Solid-State Circuits, vol. 46, no. 46, pp. 1464-1477, Jun. 2011.
    [27] S.-W. Wang, Y.-J. Woo, Y.-S. Yuk, B. Lee, G.-H. Cho, and G.-H. Cho, "Low-ripple hysteretic-controlled monolithic buck converter with adapted switching frequency for large step-down ratio applications," in Proc. IEEE Appl. Power Electronics Conf., 2011, pp. 1512-1515.
    [28] S. C. Huerta et al., "Hysteretic Mixed-Signal Controller for High-Frequency DC-DC Converters Operating at Constant Switching Frequency," IEEE Trans. Power Electron., vol. 27, no. 6, pp. 2690-2696, Jun. 2012.
    [29] S. C. Huerta et al., "Advanced Control for Very Fast DC-DC Converters Based on Hysteresis of the Cout Current," IEEE Trans. Circuits Syst. I, Reg. Papers, vol. 60, no. 4, pp. 1052-1061, Apr. 2013.
    [30] C. H. Tso and J. C. Wu, "A Ripple Control Buck Regulator With Fixed Output Frequency," IEEE Power Electron. Lett., vol. 1, no. 3, pp. 61-63, Sep. 2003.
    [31] Y. Zheng, H. Chen, and K. N. Leung, "A Fast-Response Pseudo-PWM Buck Converter With PLL-Based Hysteresis Control," IEEE Trans. Very Large Scale Integr. (VLSI) Syst., vol. 20, no. 7, pp. 1167-1174, Jul. 2012.
    [32] Q. Khan, A. Elshazly, S. Rao, et al., “A 900mA 93% Efficiency 50uA Quiescent Current Fixed Frequency Hysteretic Buck Converter Using a Highly Digital Hybrid Voltage- and Current-mode Control” in Symposium om VLSI Circuits Digest of Technical Papers, 2012, pp. 182-183.
    [33] L. K. Wong and T. K. Man, "Steady State Analysis of Hysteretic Control Buck Converters," in 13th Power Electronics and Motion Control Conference, 2008, pp. 400-404.

    [34] Texas Instrument, “Programmable Synchronous-Buck Regulator Controller ” TPS5210 datasheet, Sep. 1998 [Revised May 1999]
    [35] Texas Instrument, “High Frequency Programmable Hysteretic Regulator Controller” TPS5211 datasheet, Sep. 1998
    [36] Texas Instrument, “15V, 75mA High Efficient Buck Converter” TPS62120 datasheet, Jul. 2010
    [37] L.Chen,“Conversion circuit with hysteresis control and power supply system,” W.O.Partent 2011137707 A2, Nov,10,2011
    [38] S. Mishra, "Dynamic modeling of a hysteretic modulator," in IEEE Int. Symp. Industrial Electron., 2010, pp. 798-802.
    [39] S. Chunping and J. L. Nilles, "High-accuracy hysteretic current-mode regulator for powering microprocessors," in Proc. IEEE Appl. Power Electronics Conf., 2006, pp. 506-509
    [40] J. J. Chen, "An Active Current-Sensing Constant-Frequency HCC Buck Converter Using Phase-Frequency-Locked Techniques," IEEE Tran. Ultrason. Ferroelectr. Freq. Control, vol. 55, no. 4, pp. 761-769, Apr. 2008.
    [41] J. J. Chen, F. C. Yang, and C. C. Chen, "A New Monolithic Fast-Response Buck Converter Using Spike-Reduction Current-Sensing Circuits," IEEE Trans. Ind. Electron., vol. 55, no. 3, pp. 1101-1111, Mar. 2008.
    [42] J.-C. Tsai, C.-L. Chen, Y.-H. Lee, H.-Y. Yang, M.-S. Hsu, and K.-H. Chen, "Modified Hysteretic Current Control (MHCC) for Improving Transient Response of Boost Converter," IEEE Trans. Circuits Syst. I, Reg. Papers, vol. 58, no. 8, pp. 1967-1979, Aug. 2011.
    [43] National Semiconductor, “LM27212 Two-Phase Current-Mode Hysteretic Buck Controller,” LM27212 datasheet, Mar. 2006.
    [44] H. C. Lin, B. C. Fung, and T. Y. Chang, "A Current-Mode Adaptive On-Time Control Scheme for Fast Transient DC-DC Converters," in Proc. IEEE Int. Symp. Circuits and Syst., 2008, pp. 2602-2605.
    [45] X. Zhou, J. Fan, and A. Huang, "Monolithic DC Offset Self-Calibration Method for Adaptive On-Time Control Buck Converter," in Proc. IEEE Energy Conversion Congress and Exposition, 2009, pp. 655-658.
    [46] J. Fan, X. Li, J. Park, and A. Huang, "A Monolithic Buck Converter Using Differentially Enhanced Duty Ripple Control," in Proc. Custom Integrated Circuits Conf., 2009, pp. 527-530.
    [47] Y.-H. Lee, W.-W. Lai, W.-Y. Pai, K.-H. Chen, M.-J. Du, and S.-H. Cheng, "Reduction of equivalent series inductor effect in constant on- time control DC-DC converter without ESR compensation," in Proc. IEEE Int. Symp. Circuits and Systems, 2011, pp. 753-756.
    [48] L. Wang, Y. Pei, X. Yang, Y. Qin, and Z. Wang, "Improving Light and Intermediate Load Efficiencies of Buck Converters With Planar Nonlinear Inductors and Variable On Time Control," IEEE Trans. Power Electron., vol. 27, no. 1, pp. 342-353, Jan. 2012.
    [49] P. H. Lan and P. C. Huang, "A High Efficiency FLL-Assisted Current-Controlled DC-DC Converter Over Light-Loaded Range," IEEE Trans. Circuits Syst. I, Reg. Papers, vol. 59, no.10, pp. 2468-2476, Oct. 2012.
    [50] Y. C. Lin, C. J. Chen, D. Chen, and B. Wang, "A Ripple-Based Constant On-Time Control With Virtual Inductor Current and Offset Cancellation for DC Power Converters," IEEE Trans. Power Electron., vol. 27, no. 10, pp. 4301-4310, Oct 2012.
    [51] C.-H. Tsai, S.-M. Lin, and C.-S. Huang, "A Fast-Transient Quasi-V2 Switching Buck Regulator Using AOT Control With a Load Current Correction (LCC) Technique," IEEE Trans. Power Electron., vol. 28, no. 8, pp. 3949-3957, Aug. 2013.
    [52] National Semiconductor, “LM2696 data sheet: 3A, Constant On Time Buck Regulator,” May. 2009.
    [53] Micrel, “MIC2164/-2/-3/C data sheet: Constant Frequency, Synchronous Buck Controllers Featuring Adaptive On-Time Control,” Feb. 2010
    [54] Texas Instrument, “3.3-V/5-V Input, D-CAP+™ Mode Synchronous Step-Down Integrated FETs Converter With 2-Bit VID”, TPS51462 datasheet, Dec. 2011.
    [55] Stouchita et al., “Constant On-time Regulator with Internal Ripple Generation and Improved Output Voltage Accuracy,” U.S. Patent 7 482 791, Jan. 27, 2009.
    [56] Wong et al., “Adaptive On-time Control for Switching Regulators,” U.S. Patent 7 782 036, Aug. 24, 2010.
    [57] Q. Song, "Modeling and design considerations of V2 controlled buck regulator," in Proc. IEEE Appl. Power Electron. Conf., 2001, pp. 507-513
    [58] P. Y. Wu and P. K. T. Mok, "A Monolithic Buck Converter With Near-Optimum Reference Tracking Response Using Adaptive-Output-Feedback," IEEE J. Solid-State Circuits, vol. 42, no. 11, pp. 2441-2450, Nov. 2007.
    [59] Y. Y. Mai and P. Mok, "A Constant Frequency Output-Ripple-Voltage-Based Buck Converter Without Using Large ESR Capacitor," IEEE Trans. Circuits Syst. II, Exp. Briefs, vol. 55, no. 8, pp. 748-752, Aug. 2008.
    [60] Y. H. Lee, S. J. Wang, and K. H. Chen, "Quadratic Differential and Integration Technique in V2 Control Buck Converter With Small ESR Capacitor," IEEE Trans. Power Electron., vol. 25, no. 4, pp. 829-838, Apr. 2010.
    [61] W. Huang, “A new control for multi-phase buck converter with fast transient response,” in Proc. IEEE APEC’01 Conf., 2001, pp. 273–279.
    [62] J. Sun, "Characterization and performance comparison of ripple-based control for voltage regulator modules," IEEE Trans. Power Electron., vol. 21, no. 2, pp. 346-353, Mar. 2006.
    [63] J. Li, and F.C Lee, "Modeling of V2 Current-Mode Control," in IEEE Appl. Power Electron. Conf. and Exposition, 2009. pp.298-304
    [64] G. Zhou, J. Xu, and J. Wang, "Constant-Frequency Peak-Ripple-Based Control of Buck Converter in CCM: Review, Unification and Duality," IEEE Trans. Ind. Electron., vol. 61, no. 3, pp. 1280-1291, Mar. 2014.
    [65] C. Song, "Accuracy Analysis of Constant-On Current-Mode DC-DC Converters for Powering Microprocessors," in Proc. IEEE Appl. Power Electron. Conf., 2009, pp. 97-101.
    [66] On Semiconductor, “1.5 A, 260 kHz and 520 kHz, Low Voltage Buck Regulators with External Bias or Synchronization Capability”, CS51411 datasheet, May. 2013.
    [67] Chunping Song, "Optimizing Accuracy of Hysteretic Control," National Semiconductor, Feb. 2006.
    [68] “A Simple Current-Sense Technique Eliminating a Sense Resistor,” AN-7 Lin Finity Application, 1998.
    [69] D. Grant, “Frequency control of hysteretic power converter by adjusting hysteresis levels” U.S. Patent 6,348,780 B1, Feb. 19, 2002
    [70] A. Mihalka, “Fixed frequency hysteretic regulator” U.S. Patent 6,885,175 B2, Apr. 26, 2005
    [71] I. MIREA “Frequency Lock Loop for Hysteretic Switching Regulators,” U.S. Patent 2013/0049711 A1, Feb. 28, 2013.
    [72] P. Li and R. Bashirullah, "A DLL Based Multiphase Hysteretic DC-DC Converter," in Proc. Int. Symp. Quality Electronic Design, 2007, pp. 98-101.
    [73] R. Bondade and M. Dongsheng, "A DLL-regulated SIMO power converter for DVS-enabled power-aware VLSI systems," in Proc. IEEE Int. Symp. Circuits and Syst., 2009, pp. 961-964.
    [74] P. Li, X. Lin, P. Hazucha, T. Karnik, and R. Bashirullah, "A Delay-Locked Loop Synchronization Scheme for High-Frequency Multiphase Hysteretic DC-DC Converters," IEEE J. Solid-State Circuits, vol. 44, no. 11, pp. 3131-3145, Nov. 2009.
    [75] K.-C. Lee, C.-s. Chae, G.-H. Cho, and G.-H. Cho, "A PLL-based high-stability single-inductor 6-channel output DC-DC buck converter," in IEEE Int. Solid-State Circuits Conf., 2010, pp. 200-201.
    [76] Roland E. Best," Phase Locked Loops: Design, Simulation, and Applications,6th Edition" McGraw Hill Professional, 2007
    [77] W. Yue and O. Trescases, "Analysis and Comparison of Frequency Stabilization Loops in Self-Oscillating Current-Mode DC-DC Converters," IEEE Trans. Power Electron., vol. 28, no.10, pp. 4753-4766, Oct. 2013.
    [78] L. Corradini, E. Orietti, P. Mattavelli, and S. Saggini, “Digital Hysteretic Voltage-Mode Control for DC-DC Converters Based on Asynchronous Sampling” IEEE Trans. Power Electron., vol. 24, no.1, pp. 201-211, Jan. 2009.
    [79] L. Corradini, A. Bjeletic, R. Zane, and D. Maksimovic, “Fully Digital Hysteretic Modulator for DC-DC Switching Converters” IEEE Trans. Power Electron., vol. 26, no.10, pp. 2969-2979, Oct. 2011.

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