一种无阈值压降的可重构高功率密度电荷泵  

A reconfigurable high power density charge pump without threshold voltage loss

作　　者：程心[1] 张涵 陈亮 张章[1] CHENG Xin;ZHANG Han;CHEN Liang;ZHANG Zhang(School of Electronic Science and Applied Physics, Hefei University of Technology, Hefei 230601, China;Anhui Academy of Science and Technology, Hefei 230088, China)

机构地区：[1]合肥工业大学电子科学与应用物理学院,安徽合肥230601 [2]安徽省科学技术研究院,安徽合肥230088

出　　处：《合肥工业大学学报（自然科学版）》2020年第4期487-492,共6页Journal of Hefei University of Technology：Natural Science

基　　金：国家自然科学基金资助项目(61674049);中央高校基本科研业务费专项资金资助项目(PA2018GDQT0017)。

摘　　要：文章通过折叠浮置电容的方法实现电荷泵片上实时重构,解决了可重构电荷泵中开关路径过多以及低电压转换倍率(voltage conversion ratio,VCR)时部分电容闲置的问题,降低了电荷泵内阻,提高了功率密度,降低了输出电压纹波;在此基础上,提出新的电平转换器(level shifter,LS)来产生开关管的控制信号,以消除开关管的阈值压降;同时采用双路LS交替输出的方法,使开关管的控制信号保持适当的死区时间,减小了反向电流。文中以4阶电荷泵为例,基于TSMC CMOS 0.18μm工艺库仿真验证了上述方案的可行性,该结构可在2×、3×、4×、5×这4种VCR之间实时转换,工作电压低至金属氧化物半导体(metal oxide semiconductor,MOS)管阈值电压,空载条件下的输出电压能够达到理想值的97%以上。In order to realize an on-chip real-time reconfigurable charge pump,the method of folding flying capacitor is adopted,which solves the problems of excessive switch paths in reconfigurable charge pump and idle capacitors in lower voltage conversion ratio(VCR)at the same time.It can decrease internal resistance of charge pump,improve power density and reduce output voltage ripple.On this basis,a new level shifter(LS)is designed to generate control signals of switches,thus eliminating the threshold voltage loss of the switches.At the same time,two-link LSs output control signals alternately to keep appropriate dead time of control signals,thus decreasing reverse current.Taking fourth-stage charge pump as an example,the feasibility of the above schemes is verified by the simulation based on TSMC CMOS 0.18μm process library.Results show that this structure can realize real-time adjustment of VCRs among 2×,3×,4×and 5×.The lowest operating voltage can reach the threshold voltage of N-channel metal oxide semiconductor(NMOS)switches and the output voltage of charge pump can reach more than 97%of ideal value under no-load condition since there is no threshold voltage loss and reverse current decreases.

关 键 词：电荷泵 可重构 电平转换器(LS) 阈值压降 反向电流 

分 类 号：TN432[电子电信—微电子学与固体电子学]