采用AB类源跟随器的无片外电容快速瞬态响应LDO  

A capacitor-less LDO with fast transient response based on class-AB super source follower

作　　者：姚方舟 张章[1] YAO Fangzhou;ZHANG Zhang(School of Electronic Science and Applied Physics,Hefei University of Technology,Hefei 230601,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

出　　处：《合肥工业大学学报（自然科学版）》2022年第4期475-480,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(U19A2053)。

摘　　要：文章提出一种快速响应、高稳定性、无片外电容的低压差线性稳压器(low dropout regulator,LDO),应用于无线能量传输系统中的接收端电源管理。采用电容耦合方式感知负载变化,可以有效检测输出端负载跳变,在负载瞬间跳变时增大功率器件栅极电容的充放电电流,具有摆率增强的作用,增强瞬态响应。缓冲级采用AB类超级源跟随器,实现了动态电流提升,且不会降低电源电压要求或增加静态功耗;同时,引入负反馈实现低阻抗转化将次极点推到更高的频率,提高环路的相位裕度。采用CSMC 0.35μm的CMOS工艺进行设计和仿真。仿真结果表明:输入电压为2.1~4.8 V时,该LDO的输出电压为1.2 V,最大负载电流为300 mA;负载电流在2~300 mA之间变化时,输出电压的最大上冲值和下冲值分别为111、188 mV,响应时间分别为3.2、2.1μs。A capacitor-less low dropout regulator(LDO)with fast transient response and high stability based on class-AB super source follower was proposed,which was applied to the receiving end of wireless energy transmission system.The capacitance coupling technology was used to sense the load change,which could effectively detect the load jump at the output end.It could also increase the charge and discharge current of the gate capacitance of the power device when the load jumped instantly,which would enhance the slew rate and the transient response.Class-AB super source follower was adopted in the buffer stage to achieve dynamic current increase without reducing power supply voltage requirements or increasing static power consumption.The negative feedback was introduced to achieve low impedance conversion,pushing the sub-pole to a higher frequency and improving the phase margin of the loop.CSMC 0.35μm CMOS process was used for the design and simulation.The simulation results showed that when the input voltage changed between 2.1 V and 4.8 V,the output voltage of the LDO was 1.2 V,and the maximum load current was 300 mA.When the load current changed between 2 mA and 300 mA,the maximum overshoot and undershoot of the output voltage were 111 mV and 188 mV,and the response times were 3.2μs and 2.1μs,respectively.

关 键 词：低压差线性稳压器(LDO) 摆率增强 快速瞬态响应 AB类超级源跟随器 无片外电容 缓冲级 

分 类 号：TN432[电子电信—微电子学与固体电子学]