Analog Integrated Circuits and Signal Processing

, Volume 101, Issue 3, pp 555–564 | Cite as

Dynamic current-boosting based FVF for output-capacitor-less LDO regulator

  • Fatemeh Abdi
  • Yasin Bastan
  • Parviz AmiriEmail author


A flipped voltage follower structure based on a dynamic current boosting technique is proposed which enables the fast-transient behavior. It is applied to an output capacitor-less low-dropout (LDO) regulator to improve the output transient response and reduce the over/undershoots of the output voltage when the load current or the input voltage is suddenly changed. The proposed low-dropout regulator is simulated in 0.18 μm CMOS technology, which the output voltage is regulated at 1 V with a dropout voltage of about 114 mV. The output voltage over/undershoot amplitudes of the proposed LDO are obtained in 99.52/551.8 mV with the settling time of fewer than 1.3 μs for the load current changes from 0.1 to 100 mA with 200 ns rise/fall times.


Capacitor-less low-dropout regulator Flipped voltage follower Dynamic current-boosting Fast transient response CMOS 



  1. 1.
    Lee, Y.-H., Yang, Y.-Y., Wang, S.-J., Chen, K.-H., Lin, Y.-H., Chen, Y.-K., et al. (2011). Interleaving energy-conservation mode (IECM) control in single-inductor dual-output (SIDO) step-down converters with 91% peak efficiency. IEEE Journal of Solid-State Circuits,46(4), 904–915.CrossRefGoogle Scholar
  2. 2.
    Chen, Y., Kang, Y., Nie, S., & Pei, X. (2011). The multiple-output DC–DC converter with shared ZCS lagging leg. IEEE Transactions on Power Electronics,26(8), 2278–2294.CrossRefGoogle Scholar
  3. 3.
    Carvajal, R., Ramirez-Angulo, J., Lopez-Martin, A., Torralba, A., Galan, J., Carlosena, A., et al. (2005). The flipped voltage follower: A useful cell for low-voltage low-power circuit design. IEEE Transactions on Circuits and Systems I: Regular Papers,52(7), 1276–1291.CrossRefGoogle Scholar
  4. 4.
    Saberkari, A., Alarcón, E., & Shokouhi, S. B. (2013). Fast transient current-steering CMOS LDO regulator based on current feedback amplifier. Integration,46(2), 165–171.CrossRefGoogle Scholar
  5. 5.
    Cong, P., Chaimanonart, N., Ko, W. H., & Young, D. J. (2009). A wireless and batteryless 10-bit implantable blood pressure sensing microsystem with adaptive RF powering for real-time laboratory mice monitoring. IEEE Journal of Solid-State Circuits,44(12), 3631–3644.CrossRefGoogle Scholar
  6. 6.
    Ho, M., Leung, K. N., & Mak, K.-L. (2010). A low-power fast-transient 90-nm low-dropout regulator with multiple small-gain stages. IEEE Journal of Solid-State Circuits,45, 2466–2475.Google Scholar
  7. 7.
    Wong, L., Hossain, S., Ta, A., Edvinsson, J., Rivas, D., & Naas, H. (2004). A very low-power CMOS mixed-signal IC for implantable pacemaker applications. IEEE Journal of Solid-State Circuits,39(12), 2446–2456.CrossRefGoogle Scholar
  8. 8.
    Nasrollahpour, M., Hamedi-Hagh, S., Bastan, Y., & Amiri, P. (2017). ECP technique based capacitor-less LDO with high PSRR at low frequencies, − 89 dB PSRR at 1 MHz and enhanced transient response. In 2017 14th international conference on synthesis, modeling, analysis and simulation methods and applications to circuit design (SMACD).Google Scholar
  9. 9.
    Or, P. Y., & Leung, K. N. (2010). A fast-transient low-dropout regulator with load-tracking impedance adjustment and loop-gain boosting technique. IEEE Transactions on Circuits and Systems II: Express Briefs,57(10), 757–761.CrossRefGoogle Scholar
  10. 10.
    Fathipour, R., Saberkari, A., Martinez, H., & Alarcón, E. (2014). High slew rate current mode transconductance error amplifier for low quiescent current output-capacitorless CMOS LDO regulator. Integration,47(2), 204–212.CrossRefGoogle Scholar
  11. 11.
    Man, T. Y., Mok, P. K. T., & Chan, M. (2007). A high slew-rate push-pull output amplifier for low-quiescent current low-dropout regulators with transient-response improvement. IEEE Transactions on Circuits and Systems II: Express Briefs,54(9), 755–759.CrossRefGoogle Scholar
  12. 12.
    El-Nozahi, M., Amer, A., Torres, J., Entesari, K., & Sanchez-Sinencio, E. (2010). High PSR low drop-out regulator with feed-forward ripple cancellation technique. IEEE Journal of Solid-State Circuits,45(3), 565–577.CrossRefGoogle Scholar
  13. 13.
    Serdijn, W. A., Woerd, A. C., Roermund, A. H. M., & Davidse, J. (1995). Design principles for low-voltage low-power analog integrated circuits. Low-Voltage Low-Power Analog Integrated Circuits,8, 115–120.CrossRefGoogle Scholar
  14. 14.
    Man, T. Y., Leung, K. N., Leung, C. Y., Mok, P., & Chan, M. (2008). Development of single-transistor-control LDO based on flipped voltage follower for SoC. IEEE Transactions on Circuits and Systems I: Regular Papers,55(5), 1392–1401.MathSciNetCrossRefGoogle Scholar
  15. 15.
    Blakiewicz, G. (2011). Output-capacitorless low-dropout regulator using a cascoded flipped voltage follower. IET Circuits, Devices and Systems,5(5), 418.CrossRefGoogle Scholar
  16. 16.
    Ho, M., & Leung, K. N. (2011). Dynamic bias-current boosting technique for ultralow-power low-dropout regulator in biomedical applications. IEEE Transactions on Circuits and Systems II: Express Briefs,58(3), 174–178.CrossRefGoogle Scholar
  17. 17.
    Ramirez-Angulo, J., Gupta, S., Padilla, I., Carvajal, R., Torralba, A., Jimenez, M., & Munoz, F. (2005). Comparison of conventional and new flipped voltage structures with increased input/output signal swing and current sourcing/sinking capabilities. In 48th midwest symposium on circuits and systems. Google Scholar
  18. 18.
    Bastan, Y., Janipoor-Deylamani, M., & Amiri, P. (2018). Fast-transient capacitor-less low-dropout regulator with input current-differencing and dynamic current-boosting. Analog Integrated Circuits and Signal Processing. Scholar
  19. 19.
    Elwan, H., Gao, W., Sadkowski, R., & Ismail, M. (2000). CMOS low-voltage class-AB operational transconductance amplifier. Electronics Letters,36(17), 1439.CrossRefGoogle Scholar
  20. 20.
    Banker, G. P., & Naik, A. P. (2011). Comparative analysis of low power CMOS class—A voltage followers with current mirror as a load. IJECT,2(2), 108–111.Google Scholar
  21. 21.
    Bastan, Y., Hamzehil, E., & Amiri, P. (2016). Output impedance improvement of a low voltage low power current mirror based on body driven technique. Microelectronics Journal,56, 163–170.CrossRefGoogle Scholar
  22. 22.
    Abdi, F., Deylamani, M. J., & Amiri, P. (2017). Slew rate and transient response enhancement in MOLDO with modifying error amplifier structure. Journal of Circuits, Systems and Computers,26(12), 1750197.CrossRefGoogle Scholar
  23. 23.
    Lim, C.-C., Lai, N.-S., Tan, G.-H., & Ramiah, H. (2015). A low-power fast transient output capacitor-free adaptively biased LDO based on slew rate enhancement for SoC applications. Microelectronics Journal,46(8), 740–749.CrossRefGoogle Scholar
  24. 24.
    Ho, M., Guo, J., Mak, K. H., Goh, W. L., Bu, S., Zheng, Y., et al. (2016). A CMOS low-dropout regulator with dominant-pole substitution. IEEE Transactions on Power Electronics,31(9), 6362–6371.CrossRefGoogle Scholar
  25. 25.
    Li, C., & Chan, P. K. (2017). FVF LDO regulator with dual dynamic-load composite gain stage. Analog Integrated Circuits and Signal Processing,92(1), 131–140.CrossRefGoogle Scholar
  26. 26.
    Perez-Bailon, J., Marquez, A., Calvo, B., & Medrano, N. (2017). An all-MOS low-power fast-transient 1.2 V LDO regulator. In 2017 13th conference on Ph.D. research in microelectronics and electronics (PRIME).Google Scholar
  27. 27.
    Yosef-Hay, Y., Larsen, D. Ø., Muntal, P. L., & Jørgensen, I. H. H. (2017). Fully integrated, low drop-out linear voltage regulator in 180 nm CMOS. Analog Integrated Circuits and Signal Processing,92(3), 427–436.CrossRefGoogle Scholar
  28. 28.
    Joo, S., & Kim, S. (2018). Output-capacitor-free LDO design methodologies for high EMI immunity. IEEE Transactions on Electromagnetic Compatibility,60(2), 497–506.CrossRefGoogle Scholar

Copyright information

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

Authors and Affiliations

  1. 1.Microelectronics and Industrial Equipment Research Laboratory, Electrical Engineering Faculty/Electronics DepartmentShahid Rajaee Teacher Training University (SRTTU)Lavizan, TehranIran

Personalised recommendations