适用于高精度BUCK变换器的驱动及保护电路研究与设计

发布时间：2018-09-19 08:26

【摘要】：随着现代电子技术的飞速发展,便携式电子设备的功能更加多样化而且发展非常成熟,尤其是它的携带方便等显著特点使得电子产品已经成为人们生活中必不可少的一部分。电源作为电子产品的重要组成部分,对电源管理的性能要求也越发的挑剔。在各种各样的电源管理方式中,以开关电源的转换效率为最高(达到90%以上),可以有效的避免能源的浪费,符合节能减排等当前国际形势和发展趋势;另外,开关电源技术还具有高可靠性、重量轻、高速率、抗干扰能力强等优势,开关电源已经被广泛用于电子产品的各个领域。为了满足不同的性能指标和种类繁多的新型电子设备,开关电源的研究和开发一直是非常热门的方向。在开关电源中,功率管及其驱动电路的设计在提高芯片整体的转换效率中起着决定性作用;软启动电路、过温保护、欠压过压等保护电路是确保系统工作在一个安全的环境,为了提高芯片的整体可靠性必不可少。因此,对它们的研究和改进是很有必要的,对于提高开关电源的整体性能也是非常重要的。本文首先阐述DC-DC开关电源的基本理论知识和当前开关电源方面的主要做法,对开关电源的主要模块分别进行理论和原理分析,解析这些做法的优缺点。经过综合分析,确定本文要设计的恒定导通时间控制的DCDC变换器,并针对本文所主要关注的驱动电路和保护电路的相关理论进行重点分析,对设计驱动模块可能出现的问题进行了剖析,如死区设置问题、防穿通保护问题等。再者针对本文重点设计的软启动模块、驱动模块、输出异常保护模块、过温保护电路进行了严谨的电路设计及仿真验证。模块功能符合总架构规划要求,性能稳定,逻辑控制能够达到系统要求。最后基于0.35μm BCD工艺,运用Cadence下的Spectre仿真软件对系统的整体稳定性和可靠性进行了整体仿真。从仿真结果可以看出,该架构实现了输入电压4.5~28V,输出电压最低电压0.8V的BUCK变换器的实现方式,具有响应速度快,精度高、系统稳定度高等优点。
[Abstract]:With the rapid development of modern electronic technology, the functions of portable electronic devices are more diversified and mature. Especially, the advantages of portable electronic devices make electronic products become an indispensable part of people's life. As an important part of electronic products, power supply is more and more critical to the performance of power management. Among all kinds of power management methods, switching power supply has the highest conversion efficiency (more than 90%), which can effectively avoid the waste of energy and conform to the current international situation and development trend of energy saving and emission reduction. Switching power supply technology also has the advantages of high reliability, light weight, high speed, strong anti-jamming ability and so on. Switching power supply has been widely used in various fields of electronic products. The research and development of switching power supply has been a very popular direction in order to meet different performance indexes and a variety of new electronic equipment. In the switching power supply, the design of power transistor and its driving circuit plays a decisive role in improving the overall conversion efficiency of the chip, and the protection circuits such as soft start circuit, over-temperature protection and under-voltage overvoltage are used to ensure that the system works in a safe environment. In order to improve the overall reliability of the chip is essential. Therefore, it is necessary to study and improve them, and it is also very important to improve the overall performance of switching power supply. In this paper, the basic theoretical knowledge of DC-DC switching power supply and the current main methods of switching power supply are described. The main modules of switching power supply are analyzed in theory and principle, and the advantages and disadvantages of these methods are analyzed. After comprehensive analysis, the DCDC converter with constant on-time control is designed, and the related theories of driving circuit and protection circuit are analyzed in detail. The possible problems in the design of driving module are analyzed, such as the dead zone setting problem, the problem of preventing penetration through protection and so on. Thirdly, the design and simulation of the soft start module, the driving module, the output abnormal protection module and the over-temperature protection circuit are carried out. The function of the module meets the requirements of the general architecture planning, the performance is stable, and the logic control can meet the requirements of the system. Finally, based on 0.35 渭 m BCD process, the overall stability and reliability of the system are simulated by Spectre simulation software under Cadence. It can be seen from the simulation results that the BUCK converter with the input voltage of 4.5 ~ 28V and the lowest output voltage of 0.8V has the advantages of fast response speed, high precision and high system stability.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM46

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