低功耗无片外电容LDO集成电路的研究与设计-集成电路工程专业论文.docxVIP

万方数据 万方数据 摘 要 摘 要 电源管理芯片作为电源系统中必不可少的组成部分，其性能的好坏直接影响着电 源的使用时间。低压差线性稳压器（Low Dropout regulator，LDO）作为电源管理芯 片中重要的组成部分，其工作电压范围宽，输出电压稳定，并且还具有输出噪声低、 结构简单等优点，在电子设备中得到了广泛的应用。无片外电容型（Output Capacitor- less，OCL）LDO 相对于传统 LDO 而言，没有了其外接大电容，体积更小、成本更 低，非常适合于片上系统（System on Chip，SOC）的应用，已成为研究的热点之一。 此外，为了延长系统的待机时间，低功耗一直是科研人员追求的一个重要目标，因此 低功耗无片外电容 LDO 成为当今研究的热点之一。 本文介绍了 LDO 的发展前景和基本结构及性能参数，在着重分析影响 LDO 瞬态 响应和稳定性各种因素，并和无片外电容 LDO 进行对比分析的基础上，寻求优化无 片外电容 LDO 瞬态响应和稳定性的方法。通过在电路中引入电荷泄放电路和电流倍 增缓冲级来提高调整管栅极电容的充放电速度来改善稳压器的瞬态响应；采用二级密 勒补偿技术保证电路在各种负载条件下的稳定性；通过使 MOS 管工作在亚阈值的方 式来降低系统功耗。基于以上研究，采用 SMIC 0.18-?m CMOS 工艺对该无片外电容 LDO 电路进行设计、仿真验证，并流片测试，测试结果表明：在负载电流为 1 mA、 输入电压为 1.9-3.2 V 时，输出电压可稳定在 1.8 V 左右，压差仅为 35 mV，且静态电 流仅为 1.4 ?A。 关键词：LDO 线性稳压器；无片外电容 LDO；超低功耗 I Ab Abstract Abstract Power is an indispensable part of any equipments and systems. And power management is important for portable electronic devices in order to enhance the system quality and increase the battery runtime. Low-Dropout regulators(LDO) are widely used either alone in many integrated power management circuits, while they can provide wideband and reliable regulated low noise supply voltage for noise-sensitive analog and RF loads. Most of conventional LDOs use a large capacitor, which cannot be implemented on chip. Therefore, output-capacitorless LDOs are needed for SoC applications. In order to extend the system runtime, the low power consumption has been an important aim of scientific researchers. So low power consumption of output-capacitorless LDO become one of the hot spot of current research. In this paper, the development of the future, the basic structure and performance parameters are introduced firstly. Then, various factors which influence the stability of transient response, and compare the OCL-LDO find the optimal method of OCL-LDO are analyzed. While an instantaneous current-boosting voltage buffer is inserted to improve the transient responses. The stability and transient responses of the LDO regulator are presented, and it