摘要
无片外电容低压差线性稳压器(LDO)可以为高度集成的片上系统(SoC)提供低噪声、低纹波的电源电压。针对无片外电容LDO瞬态响应速度较慢、稳定性较差的问题,采用有源前馈补偿技术加快功率管的充放电速率,提高LDO的瞬态响应速度;且引入左半平面零点,改善系统的稳定性。同时,前馈补偿电路可以使LDO在轻载和重载之间变化时,自适应地在二级级联放大器和三级级联放大器结构之间切换,确保LDO在全负载范围内保持稳定。采用TSMC 0.18μm CMOS工艺进行电路的设计。仿真结果表明,在片上负载电容为20 pF且负载电流在0~200 mA变化时,设计的无片外电容LDO能够工作在1.7~2.8 V的输入电源电压下,稳定输出1.5 V的供电电压,系统在全负载范围内的相位裕度大于45°。当负载电流在1μs内,在0 mA和200 mA之间跳变时,过冲和下冲电压小于100 mV,恢复时间低于0.6μs。设计的LDO在高稳定性、快速瞬态响应和宽负载范围方面取得了较好的性能。
Low-dropout regulator(LDO)without external capacitors can provide low noise and low ripple power supply voltage for highly integrated on-chip system(SoC).To address slow transient response speed and poor stability of the capacitor-free LDO,active feedforward compensation technology was adopted to accelerate the charging and discharging rate of power transistors to promote the transient response speed of LDO;and introduce the left half-plane zeros to improve the stability of the system.Meanwhile,the feedforward compensation circuit can adaptively switch between the two-stage cascaded amplifier and the three-stage cascaded amplifier structures when the LDO changed between light and heavy loads,ensuring that the LDO remained stable throughout the full load range.The circuit was designed using the TSMC 0.18μm CMOS technology.The simulation results show that when the on-chip load capacitance is 20 pF and the current load varies from 0 to 200 mA,the designed capacitor-free LDO can operate at an input power supply voltage of 1.7 to 2.8 V,stably output a power supply voltage of 1.5 V,and the system has a phase margin of more than 45°across the full load range.The overshoot and undershoot voltages are less than 100 mV when the load current jumps between 0 mA and 200 mA within 1μs,and the recovery time is less than 0.6μs.The designed LDO has achieved good performance in high stability,fast transient response,and wide load range.
作者
孙帆
黄海波
卢军
王卫华
彭国生
Sun Fan;Huang Haibo;Lu Jun;Wang Weihua;Peng Guosheng(School of Electrical and Information Engineering,Hubei University of Automotive Technology,Shiyan 442002,China)
出处
《电子测量技术》
北大核心
2024年第17期31-37,共7页
Electronic Measurement Technology
基金
湖北省技术创新专项(揭榜制)科技项目(2023BEB015)
湖北省教育厅科学技术研究项目(Q20221805)资助。
