Skip to main content

Advertisement

SpringerLink
Log in

A novel low quiescent current PFM method with independent threshold for buck switching converters

  • Published:
Analog Integrated Circuits and Signal Processing Aims and scope Submit manuscript

Abstract

Efficiency is the key parameter of switching converters. Pulse frequency modulation (PFM) is often used to reduce the dynamic loss at the light load condition, while Pulse width modulation (PWM) is used in heavy load case. The efficiency at the heavy load is usually process dependent, however there are many circuits design considerations for the efficiency and other electrical performances improvement in the light load case. This paper will propose a method which can operate in the PWM in heavy load condition and automatically change to the PFM in light load condition with accurate PFM current threshold independent to input voltage, output voltage, switching frequency and inductor value. The adaptive accurate zero cross comparator (AAZCC) for DCM (discontinuous mode) and the method to achieve very low quiescent current consumption in the skip period are also introduced, those two are the points to further improve the efficiency in light or medium load conditions. A prototype has been designed with a 0.18 μm CMOS process.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17
Fig. 18
Fig. 19
Fig. 20
Fig. 21
Fig. 22
Fig. 23
Fig. 24
Fig. 25
Fig. 26

Similar content being viewed by others

References

  1. Chang, R. C.-H., Chen, H.-M., Chia, C.-H., & Lei, P.-S. (2009). An exact current-mode PFM boost converter with dynamic stored energy technique. IEEE Transactions on Power Electronics, 24(4), 1129–1134.

    Article  Google Scholar 

  2. Sahu, B., & Rincón-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, 54(2), 312–321.

    Article  Google Scholar 

  3. Das, N., & Kazimierczuk, M.K. (2005). Power losses and efficiency of buck PWM DC–DC power converter. In Proceedings on electrical insulation conference and electrical manufacturing expo (pp. 417–423). Baltimore: IEEE.

  4. Man, T. Y., Mok, P. K. T., & Chan, M. (2008). An auto-selectable-frequency pulse-width modulator for buck converters with improved light-load efficiency. In IEEE international solid-state circuits conference (pp. 440–626). San Francisco: IEEE.

  5. Mulligan, M. D., Broach, B., & Lee, T. H. (2007). A 3 MHz low-voltage buck converter with improved light load efficiency. In IEEE international solid-state circuits conference (pp. 528–620). San Francisco: ISSCC.

  6. Leung, C. Y., Mok, P. K. T., Leung, K. N., & Chan, M. (2005). An integrated CMOS current-sensing circuit for low-voltage current-mode buck regulator. IEEE Transactions on Circuits and Systems, 52(7), 394–397.

    Article  Google Scholar 

  7. Lam, Y. -H., Ki, W. -H., Tsui, C.-Y., & Ma, D. (2004). Integrated 0.9 V charge-control switching converter with self-biased current sensor. In The 47th IEEE international midwest symposium on circuits and systems. Rio de Janeiro: ISCAS.

  8. Pooya, F.-Z. H., & Rincon-Mora, G. A. (2007). An accurate, continuous, and lossless self-learning CMOS current-sensing scheme for inductor-based dc–dc converters. IEEE Journal of Solid-State Circuits, 42(3), 665–679.

    Article  Google Scholar 

  9. Mengmeng, D., & Lee, H. (2010). An integrated speed- and accuracy-enhanced CMOS current sensor with dynamically biased shunt feedback for current-mode buck regulators. IEEE Transactions on Circuits and Systems, 57(10), 2804–2814.

    Article  MathSciNet  Google Scholar 

  10. National Semiconductor Corporation (2008). Datasheet of LM20133. Santa Clara: National Semiconductor Corporation.

  11. Linear Technology (2008). Datasheet of LTC3414. Milpitas: Linear Technology Corporation.

  12. Maxim (2009). Datasheet of MAX15038. Sunnyvale: Maxim Corporation.

  13. Texas Instruments (2009). Datasheet of TPS54617. Dallas: Texas Instruments Corporation.

  14. Analog Devices (2009). Datasheet of ADP2118. Norwood: Analog Devices Corporation.

  15. Erickson, R. W., & Maksimovic, D. (2000). Fundamentals of power electronics (2nd ed.). New York: Springer.

  16. Lee, C. F., & Mok, P. K. T. (2004). A monolithic current-mode CMOS DC–DC converter with on-chip current-sensing technique. IEEE Journal of Solid-State Circuits, 39, 3–14.

    Article  Google Scholar 

Download references

Acknowledgments

The author would like to thank the power management teams in Shanghai and Japan Design Centers, Analog Devices Inc; as well as the state key laboratory of ASIC and system, Fudan University.

Author information

Authors and Affiliations

  1. State Key Laboratory of ASIC and System, Fudan University, Shanghai, China

    Bin Shao

  2. Analog Devices, Shanghai, China

    Bin Shao

Authors
  1. Bin Shao
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Bin Shao.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Shao, B. A novel low quiescent current PFM method with independent threshold for buck switching converters. Analog Integr Circ Sig Process 75, 225–236 (2013). https://doi.org/10.1007/s10470-012-9933-5

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10470-012-9933-5

Keywords

Search

Navigation