论文总字数：29635字

摘 要

随着智能家居、新能源汽车、智能机器人等应用的快速发展，智能功率模块因其结构与功能上的高集成度正逐渐取代传统功率模块，在电机驱动领域受到了广泛的关注与应用。LDO（低压降线性稳压器）作为智能功率模块中的关键模块，可以将输入的15V电压转为5V，给内部数字电路供电，它的精度性能将直接影响着智能功率模块预警、保护、控制功能的实现。因此，研究一款高精度的15V转5V片上LDO是提升智能功率模块内部供电电源性能的保证。

本文重点围绕片上LDO的精度性能展开了详细的理论研究，分析了工艺变化、温度变化、电源波动、负载变化等对精度的影响，创新提出了一种以二极管连接的MOS管作为负载的共源级放大器来充当误差放大器电路与NMOS功率晶体管之间的缓冲级电路，实现了负载电流以1us的上升沿从0mA突变至50mA时仅231mV的电压欠冲量及以1us的下降沿从50mA突变至0mA时仅290mV的电压过冲量，同时建立时间均在5us之内；与此同时，本文在带隙基准电路中增加了预稳压电路，将带隙基准的线性调整率降低至了3.4mV/V。

此外，本文也关注并优化了片上LDO的集成度、静态电流、稳定性等性能。在集成度提升方面，本文使用NMOS作为功率晶体管，可以在保证LDO稳定性的同时降低对负载电容的要求，本文的负载电容仅为50pF的片上电容；在静态电流方面，本文利用了NMOS功率晶体管的体效应，将静态电流降低至了140uA；在稳定性方面，通过在误差放大器电路与缓冲级电路之间加入密勒补偿电路，整个开环回路增益可以达到63dB，相位裕度可以达到40°以上。

最后，仿真结果显示本文设计的LDO负载调整率仅为0.04%，即使在瞬态响应下也具有5.8%的精度，完全达到既定指标。

关键词：智能功率模块，低压降线性稳压器，高精度，片上，

Abstract

With the development of smart homes, new energy vehicles, and intelligent robots, intelligent power modules are gradually replacing conventional power modules because of their high degree of structural and functional integration, and have received more extensive attention in the field of motor drives. As a key module in the intelligent power module, the LDO( Low-Dropout Regulator) can convert the input 15V to 5V to supply power to the internal digital circuit. Its accuracy performance will directly affect the realization of the intelligent power module's early warning, protection, and control functions. Therefore, researching a high-precision 15V to 5V on-chip LDO is a guarantee for improving the performance of internal power supply of intelligent power modules.

Detailed theoretical research is focused on the precision performance of the on-chip LDO, and the influence of process variations, temperature changes, power supply fluctuations, load changes, etc. on accuracy is analyzed. A diode-connected MOS tube used as a common source of load is proposed. The stage amplifier acts as a buffer stage circuit between the error amplifier circuit and the NMOS power transistor, achieving a voltage undershoot of only 231mV with a load current ramping from 0mA to 50mA on a rising edge of 1us and a voltage overshoot of only 290mV with a sudden change from 50mA to 0mA with a falling edge of 1us, and the settling time is within 5μs. At the same time, a pre-regulator circuit is added to the bandgap reference circuit, which reduces the linear adjustment rate of the bandgap reference to 3.4mV/V.

In addition, the on-chip LDO's integration, quiescent current, and stability are also focused and optimized. In terms of the improvement of integration, the NMOS is used as a power transistor, which can reduce the load capacitance requirements while ensuring the stability of the LDO. The load capacitance in this paper is only 50pF on-chip capacitance. In terms of quiescent current, the body effect of NMOS power transistors is used, which reduces the quiescent current to 140uA. In terms of stability, by adding a Miller compensation circuit between the error amplifier circuit and the buffer stage circuit, the overall open-loop gain can reach 63dB, and the phase margin can reach more than 40°.

Finally, the simulation results show that the LDO load regulation rater is only 0.04%. Even with the transient response, it has an accuracy of 5.8%, which fully meets the established target.

KEY WORDS: Intelligent power module, Low-Dropout Regulator, High-precision, On-chip

目 录

摘要 I

Abstract II

第一章 绪论 1

1.1 研究背景与意义 1

1.2 片上LDO的国内外研究现状与发展趋势 1

1.3 论文研究内容与设计指标 4

1.4 论文的组织结构 5

第二章 片上LDO基本原理和精度性能分析 6

2.1 片上LDO基本结构 6

2.2 片上LDO精度性能分析 6

2.2.1 工艺影响分析 7

2.2.2 温度影响分析 7

2.2.3 电源与负载影响分析 7

2.3 本章小结 11

第三章 高精度片上LDO结构设计 12

3.1 带隙基准电路设计 12

3.2 电流偏置电路设计 20

3.3 功率晶体管选择 22

3.4 LDO主体电路设计 23

3.5 本章小结 28

第四章 高精度片上LDO仿真结果与分析 29

4.1 负载调整率 29

4.2 线性调整率 29

4.3 瞬态响应 30

4.4 静态电流 32

4.5 电源纹波抑制比 32

4.6 温度特性 33

4.7 本章小结 34

第五章 总结与展望 36

致谢 37

参考文献 38

绪论

线性稳压器，通常由于其压差较小被称为低压差线性稳压器（LDO）。本文设计的高精度LDO主要用于智能功率模块中，可以为其中的数字电路提供5V供电。本章重点归纳和总结了片上LDO的相关技术与发展趋势，并针对智能功率模块的应用需要，提出了高精度片上LDO的研究内容和技术指标。

1.1 研究背景与意义

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