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A 2.5 MHz, 6 A ripple-based adaptive on-time controlled buck converter with pseudo triangular ramp compensation

  • Menglian Zhao
  • Yanxia Yao
  • Haozhou Zhang
  • Xiaobo Wu
Article
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Abstract

This paper introduces a ripple-based adaptive on-time controlled buck converter with pseudo triangular ramp compensation. Ripple-based control has its advantages over traditional PWM control of fast response and simple structure without frequency compensation network. Constant on-time (COT) control is one of the conventional ripple-based control methods, which needs large output capacitance with large ESR to guarantee the system stability, yet leading to large output ripple. In order to strengthen system stability with small output ripple and fast transient response, a novel pseudo triangular ramp compensation is proposed. Also COT control has its drawback of switching frequency variation. Therefore an adaptive on-time generator is adopted to fix switching frequency, in which VO/N2RS and Vin/N2RS are used as current sources to eliminate the effect of input/output voltage. A voltage outer loop is also adopted to improve DC precision. The power MOSFETs are integrated inside the chip. The proposed converter was implemented in 0.18 μm 5 V CMOS process. Experimental results show that the output ripple is around 20 mV. The switching frequency can be fixed at 2.5 MHz with only 1% variation. Also with 330 nH off-chip power inductor, this converter can output up to 6 A load current. Measured peak efficiency is 85%.

Keywords

Ripple-based control Pseudo triangular ramp compensation Adaptive on-time Small ripple Large current 

Notes

Acknowledgements

The paper was supported by National Natural Science Foundation of China (No. 61371032) and Zhejiang Provincial Natural Science Foundation of China (No. LY18F040001). It also gains support from Fuzhou Rockchip Electronics Co., Ltd.

References

  1. 1.
    Delagi, G. (2010). Harnessing technology to advance the next-generation mobile user-experience. In IEEE international solid-state circuit conference (pp. 18–24).Google Scholar
  2. 2.
    Wong, P., Lee, F. C., Xu, P., & Yao, K. (2002). Critical inductance in voltage regulator modules. IEEE Transactions on Power Electronics, 17(4), 485–492.CrossRefGoogle Scholar
  3. 3.
    Yao, K., Ren, Y., & Lee, F. C. (2004). Critical bandwidth for the load transient response of voltage regulator modules. IEEE Transactions on Power Electronics, 19(6), 1454–1461.CrossRefGoogle Scholar
  4. 4.
    Yao, K., Meng, Y., Xu, P., & Lee, F. C. (2002). Design considerations for VRM response based on the output impedance. In Annual IEEE applied power electronics conference and exposition (pp. 14–20).Google Scholar
  5. 5.
    Maity, A., Patra, A., Yamamura, N., & Knight, J. (2011). Design of a 20 MHz dc–dc buck converter with 84% efficiency for portable applications. In 24th annual conference on VLSI design (pp. 316–321).Google Scholar
  6. 6.
    Redl, R., & Sun, J. (2009). Ripple-based control of switching regulators—an overview. IEEE Transactions on Power Electronics, 24(12), 2669–2680.CrossRefGoogle Scholar
  7. 7.
    Sun, J. (2006). Characterization and performance comparison of ripple-based control for voltage regulator modules. IEEE Transactions on Power Electronics, 21(2), 346–353.MathSciNetCrossRefGoogle Scholar
  8. 8.
    Zhang, H. Z., Zhao, M. L., & Wu, X. B. (2015). A novel zero-current switching method for dc–dc buck converter in portable application. The Institution of Engineering and Technology, 51(23), 1913–1914.Google Scholar
  9. 9.
    Qiu, Y., Xu, M., Yao, K., Sun, J., & Lee, F. C. (2005). The multi-frequency small-signal model for buck and multiphase interleaving buck converters. In Annual IEEE applied power electronics conference and exposition (APEC) (pp. 392–398).Google Scholar
  10. 10.
    Qiu, Y., Xu, M., Yao, K., Sun, J., & Lee, F. C. (2006). Multifrequency small-signal model for buck and multiphase buck converters. IEEE Transactions on Power Electronics, 21(5), 1185–1192.CrossRefGoogle Scholar
  11. 11.
    Duan, X., & Huang, A. Q. (2006). Current-mode variable-frequency control architecture for high-current low-voltage DC–DC converters. IEEE Transactions on Power Electronics, 21(4), 1133–1137.CrossRefGoogle Scholar
  12. 12.
    Qian, T. (2013). Subharmonic analysis for buck converters with constant on-time control and ramp compensation. IEEE Transactions on Industrial Electronics, 60(5), 1780–1786.CrossRefGoogle Scholar
  13. 13.
    Qahouq, J. A., Abdel-Rahman, O., Huang, L., & Batarseh, I. (2007). On load adaptive control of voltage regulators for power managed loads: Control schemes to improve converter efficiency and performance. IEEE Transactions on Power Electronics, 22(5), 1806–1819.CrossRefGoogle Scholar
  14. 14.
    Sahu, B., & Rincon-Mora, G. A. (2007). An accurate, low-voltage, CMOS switching power supply with adaptive on-time pulse-frequency modulation (PFM) control. IEEE Transactions on Circuits and Systems—I: Regular Papers, 54(2), 312–321.CrossRefGoogle Scholar
  15. 15.
    Chen, W., Wang, C., Su, Y., Lee, Y., Lin, C., Chen, K., et al. (2013). Reduction of equivalent series inductor effect in delay-ripple reshaped constant on-time control for buck converter with multilayer ceramic capacitors. IEEE Transactions on Power Electronics, 28(5), 2366–2376.CrossRefGoogle Scholar
  16. 16.
    Li, J. (2009). Current-mode control: Modeling and its digital application. Ph. D. Dissertation, Virginia Tech, Blacksburg.Google Scholar
  17. 17.
    Yang, W. H., Huang, C. J., Huang, H. H., Lin, W. T., Chen, K. H., Lin, Y. H., et al. (2018). A constant-on-time control dc–dc buck converter with the pseudowave tracking technique for regulation accuracy and load transient enhancement. IEEE Transactions on Power Electronics, 33(7), 6187–6198.CrossRefGoogle Scholar
  18. 18.
    Jing, X., & Mok, P. K. T. (2013). A fast fixed-frequency adaptive-on-time boost converter with light load efficiency enhancement and predictable noise spectrum. IEEE Journal of Solid-State Circuits, 48(10), 2442–2456.CrossRefGoogle Scholar
  19. 19.
    Lu, D., Yu, J., & Hong, Z. (2012). A 1500 mA, 10 MHz on-time controlled buck converter with ripple compensation and efficiency optimization. In Annual IEEE applied power electronics conference and exposition (APEC), (pp. 1232–1237).Google Scholar
  20. 20.
    Jing, X., Mok, P. K. T. & Lee, M. C. (2011). Current-slope-controlled adaptive-on-time DC–DC converter with fixed frequency and fast transient response. In Proceedings of IEEE international symposium of circuits systems (pp. 1908–1911).Google Scholar
  21. 21.
    Cheng, L., Ni, J. H., Qian, Y., Zhou, M. C., Ki, W. H., Liu, B. Y., et al. (2015). On-chip compensated wide output range boost converter with fixed-frequency adaptive off-time control for LED driver applications. IEEE Transactions on Power Electronics, 30(4), 2096–2107.CrossRefGoogle Scholar
  22. 22.
    Chan, M. P., & Mok, P. K. T. (2014). A monolithic digital ripple-based adaptive-off-time DC–DC converter with a digital inductor current sensor. IEEE Journal of Solid-State Circuits, 49(8), 1837–1847.CrossRefGoogle Scholar
  23. 23.
    Wu, H. H., Wei, C. L., Hsu, Y. C., & Darling, R. B. (2015). Adaptive peak inductor-current-controlled PFM boost converter with a near-threshold startup voltage and high efficiency. IEEE Transaction on Power Electronics, 30(4), 1956–1965.CrossRefGoogle Scholar
  24. 24.
    Lin, Y. C., et al. (2012). A ripple-based constant on-time control with virtual inductor current and offset cancellation for dc power converters. IEEE Transaction on Power Electronics, 27(10), 4301–4310.CrossRefGoogle Scholar
  25. 25.
    Song, C. (2009). Accuracy analysis of constant-on current-Mode dc–dc converters for powering microprocessors. In Annual IEEE applied power electronics conference and exposition (APEC) (pp. 97–101).Google Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  • Menglian Zhao
    • 1
  • Yanxia Yao
    • 1
  • Haozhou Zhang
    • 1
    • 2
  • Xiaobo Wu
    • 1
  1. 1.Institute of VLSI DesignZhejiang UniversityHangzhouChina
  2. 2.HiSilicon Technologies Co., LtdShenzhenChina

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