An Ultra-Low Quiescent Current CMOS Low-Dropout Regulator with Small Output Voltage Variations

Xin Cheng^1*, Yizhong Yang¹, Longjie Du¹, Yang Chen^1,2, Guangjun Xie^1,2

¹School of Electronic Science and Applied Physics, Hefei University of Technology, Hefei, China.
¹State Key Lab of ASIC and System, Fudan University, Shanghai, China.
²State Key Lab of ASIC and System, Fudan University, Shanghai, China.

DOI: 10.4236/jpee.2014.24064                

Abstract

An ultra-low quiescent current low-dropout regulator with small output voltage variations and improved load regulation is presented in this paper. It makes use of dynamically-biased shunt feedback as the buffer stage and the LDO regulator can be stable for all load conditions. The proposed structure also employs a momentarily current-boosting circuit to reduce the output voltage to the normal value when output is switched from full load to no load. The whole circuit is designed in a 0.18 μm CMOS technology with a quiescent current of 550 nA. The maximum output voltage variation is less than 20 mV when used with 1 μF external capacitor.

Keywords

Ultra-Low Quiescent Current; Low-Dropout Regulator; Small Output Variations

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Rincon-Mora, G.A. and Allen, P.E. (1998) A Low-Voltage, Low Quiescent Current, Low Drop-out Regulator. IEEE Journal of Solid-State Circuits, 33, 36-44. http://dx.doi.org/10.1109/4.654935
[2]	Leung, K.N. and Mok, P.K.T. (2003) A Capacitor-Free CMOS Low-Dropout Regulator with Damping-Factor-Control Frequency Compensation. IEEE Journal of Solid-State Circuits, 38, 1691-1702. http://dx.doi.org/10.1109/JSSC.2003.817256
[3]	Al-Shyoukh, M., Lee, H. and Perez, R. (2007) A Transient-Enhanced Low-Quiescent Current Low-Dropout Regulator with Buffer Impedance Attenuation. IEEE Journal of Solid-State Circuits, 42, 1732-1742. http://dx.doi.org/10.1109/JSSC.2007.900281
[4]	Or, P.Y. and Leung, K.N. (2010) An Output-Capacitor Less Low-Dropout Regulator with Direct Voltage-Spike Detection. IEEE Journal of Solid-State Circuits, 45, 458-466. http://dx.doi.org/10.1109/JSSC.2009.2034805
[5]	Leung, K. and Ng, Y.S. (2010) A CMOS Low-Dropout Regulator with a Momentarily Current-Boosting Voltage Buffer. IEEE Transactions on Circuits and Systems I: Regular Papers, 57, 2312-2319.
[6]	Hu, J., Hu, B., Fan, Y. and Ismail, M. (2011) A 500 nA Quiescent, 100 mA Maximum Load CMOS Low-Dropout Regulator. IEEE International Conference on Electronics, Circuits and Systems, 386-389.
[7]	Guo, J., Cao, Y. and Lai, X. (2009) An Inner ESR-Fungible Compensation Technique for Ultra-Low Power Low Dropout Regulators. Analog Integrated Circuits and Signal Processing, 61, 265-270. http://dx.doi.org/10.1007/s10470-009-9302-1
[8]	Salehi, M.R. and Mohammadalinejadi, S. (2013) A Low Dropout Voltage Regulator with Enhanced Transconductance Error Amplifier and Small Output Voltage Variations. Proceeding of Iranian Electrical Engineering Conference, 1-5.
[9]	Huang, C.H., Ma, Y.T. and Liao, W.C. (2013) Design of a Low-Voltage Low-Dropout Regulator. IEEE Transactions on Very Large Scale Integration Systems, 99, 1-5.
[10]	Gutierrez, L., Roa, E. and Hernandez, H. (2009) A Current Efficient, Low-Dropout Regulator with Improved Load Regulation. IEEE Workshop on Microelectronics and Electron Devices, 1-4.
[11]	Hazucha, P., Karnik, T., Bradley, B.A., Parsons, C., Finan, D. and Borkar, S. (2005) Area-Efficient Linear Regulator with Ultra-Fast Load Regulation. IEEE Journal of Solid-State Circuits, 40, 933-940. http://dx.doi.org/10.1109/JSSC.2004.842831
[12]	Man, T.Y., Mok, P.K.T. and 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, 755-759.