一种宽负载电流范围的高效率A-COT Buck DC-DC设计  

A-COT Buck DC-DC achieving high efficiency within an ultra-wide-load range

作　　者：马骏骑 周晓笛 黄磊磊 张润曦[1] 石春琦[1] MA Junqi;ZHOU Xiaodi;HUANG Leilei;ZHANG Runxi;SHI Chunqi(Institute of Microelectronic Circuits and Systems,East China Normal University,Shanghai 200241,China)

机构地区：[1]华东师范大学微电子电路与系统研究所,上海200241

出　　处：《微电子学与计算机》2025年第2期112-119,共8页Microelectronics & Computer

基　　金：上海市科委资助(22DZ2229004);中央高校基本科研业务费专项(40500-20103-222178)。

摘　　要：提出了一种基于自适应恒定导通时间(Adaptive constant-on-time,A-COT)的Buck DC-DC芯片,在0.001~2.000 A的宽负载电流范围内实现了高效率。对于大负载,引入栅压自举电路,采用NMOS作为高边(High Side,HS)开关,以减少导通损耗。随着负载电流的减小,电路自动过渡到离散导通模式(Discrete Conduction Mode,DCM),由过零检测电路(Zero-crossing Detection,ZCD)控制,降低开关频率和开关损耗。极轻载时,电路进入低功率模式(Low-power Mode,LPM),减小控制电路的静态电流,使静态损耗最小化。为提高输出电压精度和电路稳定性,采用了Ⅲ型补偿电路,提高环路增益和相位裕度。本文提出的DC-DC变换器效率峰值达到92.38%,在1 mA负载下效率高达86.8%,在0.001~2.000 A的整个负载范围内效率均优于84.5%。This paper presents a Buck DC-DC chip based on A-COT(Adaptive Constant-On-Time),which achieves high efficiency within a load current range of 0.001-2.000 A.For heavy load,the bootstrap circuit is employed with NMOS as the High-Side(HS)switch to reduce conduction losses.As the load current decreases,the circuit seamlessly transitions into Discrete Conduction Mode(DCM)controlled by Zero-Crossing Detection circuit(ZCD)to reduce switching frequency and switch losses.For ultra-light load,the circuit enters Low Power Mode(LPM)to reduce the quiescent current of the control circuit and minimize static losses.To improve output voltage accuracy and circuit stability,type-Ⅲcompensator is implemented to enhance loop gain and improve phase margin.The proposed DC-DC converter achieves peak efficiency of 92.38%.For 1 mA load condition,efficiency achieves 86.8%.Within the entire load range of 0.001-2.000 A,the efficiency is higher than 84.5%.

关 键 词：自适应恒定导通时间 DC-DC转换器 宽负载范围 高效率 

分 类 号：TN432[电子电信—微电子学与固体电子学]