Fully Integrated Digitally Assisted Low-Dropout Regulator for a NAND Flash Memory System

In this paper, a fully integrated digitally assisted low-dropout regulator (LDO) for a NAND flash memory system is proposed and verified using 500 nm I/O CMOS transistors. By combining an amplifier (AMP)-based LDO with a comparator (CMP)-based LDO, the proposed LDO achieves both fast load response in the transient state and accurate regulation in the steady state, which are advantages of the CMP-based LDO and AMP-based LDO, respectively. Moreover, loop frequency stability is satisfied in a wide range of load currents between 0 and 150 mA by using the simple structure of the <inline-formula><tex-math notation="LaTeX">$g_{m}$</tex-math></inline-formula>-boost cell to insert an auxiliary path. For an input voltage range of 2.3–3 V and an output voltage of 2.1 V, the measured output droop is 225 mV for a 150 mA load step in the load transition time of 20 ns with the total bias current of <inline-formula><tex-math notation="LaTeX">$81\,\mu {\rm{A}}$</tex-math></inline-formula>. The fabricated prototype chip occupies <inline-formula><tex-math notation="LaTeX">$160\,\times \,610\,\mu {\rm{m}}^{2}$</tex-math> </inline-formula> with an on-chip output capacitor of 2 nF.

[1]  Philip K. T. Mok,et al.  A Capacitor-Less CMOS Active Feedback Low-Dropout Regulator With Slew-Rate Enhancement for Portable On-Chip Application , 2010, IEEE Transactions on Circuits and Systems II: Express Briefs.

[2]  Ke-Horng Chen,et al.  Smooth Pole Tracking Technique by Power MOSFET Array in Low-Dropout Regulators , 2008, IEEE Transactions on Power Electronics.

[3]  Chien-Hung Tsai,et al.  Capacitor-less low-dropout regulator with slew-rate-enhanced circuit , 2011, IET Circuits Devices Syst..

[4]  Chenchang Zhan,et al.  An Output-Capacitor-Free Adaptively Biased Low-Dropout Regulator With Subthreshold Undershoot-Reduction for SoC , 2012, IEEE Transactions on Circuits and Systems I: Regular Papers.

[5]  Ke-Horng Chen,et al.  Low-Dropout Regulators With Adaptive Reference Control and Dynamic Push–Pull Techniques for Enhancing Transient Performance , 2009, IEEE Transactions on Power Electronics.

[6]  Ka Nang Leung,et al.  A CMOS Low-Dropout Regulator With a Momentarily Current-Boosting Voltage Buffer , 2010, IEEE Transactions on Circuits and Systems I: Regular Papers.

[7]  Yong Lian,et al.  A 0.45-to-1.2-V Fully Digital Low-Dropout Voltage Regulator With Fast-Transient Controller for Near/Subthreshold Circuits , 2016, IEEE Transactions on Power Electronics.

[8]  Arijit Raychowdhury,et al.  All-Digital Low-Dropout Regulator With Adaptive Control and Reduced Dynamic Stability for Digital Load Circuits , 2016, IEEE Transactions on Power Electronics.

[9]  Le-Ren Chang-Chien,et al.  Design of the output-capacitorless low-dropout regulator for nano-second transient response , 2012 .

[10]  Martin Kinyua,et al.  Integrated 105 dB SNR, 0.0031% THD+N Class-D Audio Amplifier With Global Feedback and Digital Control in 55 nm CMOS , 2015, IEEE Journal of Solid-State Circuits.

[11]  Qiang Li,et al.  An Ultrafast Adaptively Biased Capacitorless LDO With Dynamic Charging Control , 2012, IEEE Transactions on Circuits and Systems II: Express Briefs.

[12]  J. Choma,et al.  A supply-noise-insensitive CMOS PLL with a voltage regulator using DC-DC capacitive converter , 2001, IEEE J. Solid State Circuits.

[13]  Sang Hoon Lee,et al.  High-Voltage Analog System for a Mobile NAND Flash , 2008, IEEE Journal of Solid-State Circuits.

[14]  Jiann-Jong Chen,et al.  A High-Efficiency Fast-Transient-Response Buck Converter with Analog-Voltage-Dynamic-Estimation Techniques , 2015, IEEE Transactions on Power Electronics.

[15]  Xi Qu,et al.  An Ultralow-Power Fast-Transient Capacitor-Free Low-Dropout Regulator With Assistant Push–Pull Output Stage , 2013, IEEE Transactions on Circuits and Systems II: Express Briefs.

[16]  Ehab H.E. Bayoumi,et al.  Fuzzy PLL for three-level neutral point clamped active rectifiers , 2015 .

[17]  Ka Nang Leung,et al.  Development of Single-Transistor-Control LDO Based on Flipped Voltage Follower for SoC , 2008, IEEE Transactions on Circuits and Systems I: Regular Papers.

[18]  T. Karnik,et al.  Area-efficient linear regulator with ultra-fast load regulation , 2005, IEEE Journal of Solid-State Circuits.

[19]  Quan Pan,et al.  A Fully-Integrated Low-Dropout Regulator With Full-Spectrum Power Supply Rejection , 2015, IEEE Transactions on Circuits and Systems I: Regular Papers.

[20]  Wing-Hung Ki,et al.  An NMOS-LDO Regulated Switched-Capacitor DC–DC Converter With Fast-Response Adaptive-Phase Digital Control , 2016, IEEE Transactions on Power Electronics.

[21]  Marco Ho,et al.  Dynamic Bias-Current Boosting Technique for Ultralow-Power Low-Dropout Regulator in Biomedical Applications , 2011, IEEE Transactions on Circuits and Systems II: Express Briefs.

[22]  Mohammad A. Al-Shyoukh,et al.  A Transient-Enhanced Low-Quiescent Current Low-Dropout Regulator With Buffer Impedance Attenuation , 2007, IEEE Journal of Solid-State Circuits.

[23]  Pak Kwong Chan,et al.  A 0.9-/spl mu/A Quiescent Current Output-Capacitorless LDO Regulator With Adaptive Power Transistors in 65-nm CMOS , 2013, IEEE Transactions on Circuits and Systems I: Regular Papers.

[24]  Jianping Guo,et al.  A 6-$\mu$ W Chip-Area-Efficient Output-Capacitorless LDO in 90-nm CMOS Technology , 2010, IEEE Journal of Solid-State Circuits.

[25]  Le-Ren Chang-Chien,et al.  Digitally Controlled Low-Dropout Regulator with Fast-Transient and Autotuning Algorithms , 2013, IEEE Transactions on Power Electronics.

[26]  Pui Ying Or,et al.  An Output-Capacitorless Low-Dropout Regulator With Direct Voltage-Spike Detection , 2010, IEEE Journal of Solid-State Circuits.

[27]  Man-Kay Law,et al.  Nested-Current-Mirror Rail-to-Rail-Output Single-Stage Amplifier With Enhancements of DC Gain, GBW and Slew Rate , 2015, IEEE Journal of Solid-State Circuits.

[29]  Gyu-Hyeong Cho,et al.  High-Gain Wide-Bandwidth Capacitor-Less Low-Dropout Regulator (LDO) for Mobile Applications Utilizing Frequency Response of Multiple Feedback Loops , 2016, IEEE Transactions on Circuits and Systems I: Regular Papers.

[30]  Hung-Chih Lin,et al.  An Active-Frequency Compensation Scheme for CMOS Low-Dropout Regulators With Transient-Response Improvement , 2008, IEEE Transactions on Circuits and Systems II: Express Briefs.

[31]  Jianping Guo,et al.  A CMOS Low-Dropout Regulator With Dominant-Pole Substitution , 2016, IEEE Transactions on Power Electronics.

[32]  Amit Patra,et al.  Analysis, Design, and Performance Evaluation of a Dynamically Slew Enhanced Adaptively Biased Capacitor-Less Low Dropout Regulator , 2016, IEEE Transactions on Power Electronics.

[33]  Michiel Steyaert,et al.  A 1.65 W fully integrated 90 nm bulk cmos capacitive DC-DC converter with intrinsic charge recycling , 2013, IEEE Transactions on Power Electronics.

[34]  Youngkook Ahn,et al.  5-V Buck Converter Using 3.3-V Standard CMOS Process With Adaptive Power Transistor Driver Increasing Efficiency and Maximum Load Capacity , 2012, IEEE Transactions on Power Electronics.

[35]  Pradip Mandal,et al.  Fast transient frequency control voltage regulator using push-pull dynamic leaker circuit , 2011, India International Conference on Power Electronics 2010 (IICPE2010).

[36]  Donglai Zhang,et al.  Voltage Regulator Buck Converter with a Tapped Inductor for Fast Transient Response Application , 2014, IEEE Transactions on Power Electronics.

[37]  Tsz Yin Man,et al.  A High Slew-Rate Push–Pull Output Amplifier for Low-Quiescent Current Low-Dropout Regulators With Transient-Response Improvement , 2007, IEEE Transactions on Circuits and Systems II: Express Briefs.

[38]  Yuri Terada,et al.  7.1 A low-power 64Gb MLC NAND-flash memory in 15nm CMOS technology , 2015, 2015 IEEE International Solid-State Circuits Conference - (ISSCC) Digest of Technical Papers.

[39]  Marco Ho,et al.  A Low-Power Fast-Transient 90-nm Low-Dropout Regulator With Multiple Small-Gain Stages , 2010, IEEE Journal of Solid-State Circuits.

[40]  Philip K. T. Mok,et al.  A chip-area efficient capacitor-less CMOS LDO with active feedback and damping zero compensation , 2010, 2010 53rd IEEE International Midwest Symposium on Circuits and Systems.

[41]  Ka Nang Leung,et al.  A Fast-Transient Low-Dropout Regulator With Load-Tracking Impedance Adjustment and Loop-Gain Boosting Technique , 2010, IEEE Transactions on Circuits and Systems II: Express Briefs.

[42]  Seongwon Kim,et al.  Dual-Loop System of Distributed Microregulators With High DC Accuracy, Load Response Time Below 500 ps, and 85-mV Dropout Voltage , 2012, IEEE Journal of Solid-State Circuits.

[43]  Ke-Horng Chen,et al.  A Low-Dropout Regulator With Smooth Peak Current Control Topology for Overcurrent Protection , 2010, IEEE Transactions on Power Electronics.

[44]  Chenchang Zhan,et al.  Analysis and Design of Output-Capacitor-Free Low-Dropout Regulators With Low Quiescent Current and High Power Supply Rejection , 2014, IEEE Transactions on Circuits and Systems I: Regular Papers.

[45]  Yuri Terada,et al.  A Low Power 64 Gb MLC NAND-Flash Memory in 15 nm CMOS Technology , 2016, IEEE Journal of Solid-State Circuits.

[46]  Patrick P. Mercier,et al.  A Recursive Switched-Capacitor DC-DC Converter Achieving $2^{N}-1$ Ratios With High Efficiency Over a Wide Output Voltage Range , 2014, IEEE Journal of Solid-State Circuits.