一款频率可调的高效同步BUCK型DC-DC转换器XD2825的研究设计

发布时间：2018-03-31 16:39

本文选题：BUCK型DC-DC转换器　切入点：PWM调制　出处：《西安电子科技大学》2015年硕士论文

【摘要】：随着电子信息科学技术的不断发展,便携式电子设备的使用越来越普遍,对其性能的要求也越来越高,而供电电源的性能是决定便携式电子设备性能的重要因素,因而高性能电源管理类芯片的研究与设计对于市场需求具有实际的应用意义。本论文的课题来源是基于西安电子科技大学CAD研究所的科研项目“电源管理类集成电路关键技术的研究及设计”,研究设计了一款频率可调的高效同步BUCK型DC-DC转换器XD2825。通过对模拟CMOS集成电路设计基本理论的学习与理解,并结合当前电源设备的市场需求,该转换器芯片XD2825采用PWM调制方式的峰值电流模式控制环路,具有较快的瞬态响应速度,且利用同步整流技术有效地提高了系统的转换效率。为扩展芯片XD2825的应用场合,在系统内部集成了可进行时钟频率调节的外同步模块,使芯片XD2825可工作在较宽范围的时钟频率下。为使系统能在全负载范围内均具备较高的转换效率,故集成了低功率模式,系统可根据负载的不同选择采用连续工作模式或非连续工作模式。论文将首先介绍电源管理类集成电路的研究背景、现状和发展以及开关电源的主要性能指标;其次对BUCK型DC-DC转换器的工作原理进行分析,其中包括DC-DC转换器的拓扑结构、主要工作模式、主要调制方式以及主要控制模式,为芯片XD2825系统级的研究与设计提供了理论依据;然后对芯片XD2825进行系统级的研究和设计,确定芯片XD2825的功能以及具体的电特性指标,并对系统的整体功能框图和各个功能子模块进行详细的阐述;最后对芯片XD2825进行了整体功能的仿真,验证其工作的有效性,之后对版图的设计技术进行简单介绍,同时给出了芯片XD2825的版图布局与整体版图。芯片XD2825采用0.5μm的BCD 30V制造工艺,依靠Cadence仿真环境下的Spectre仿真工具进行整体功能仿真验证。芯片XD2825将具有4.75V~20V的宽输入电压范围,内部固定时钟频率500KHz,外部可同步时钟频率300KHz~2 MHz,最大负载电流4 A,转换效率可达95%。该芯片可广泛应用于路由器、笔记本电脑和移动电源等设备中,具有转换效率高、静态功耗低和工作稳定等优点,极大地改善了便携式电子设备的电源性能。
[Abstract]:With the development of electronic information science and technology, the use of portable electronic equipment is becoming more and more common, and the performance of power supply is an important factor to determine the performance of portable electronic equipment.Therefore, the research and design of high performance power supply management chip has practical application significance to market demand.This thesis is based on the research project of CAD Institute of Xi'an University of Electronic Science and Technology, "the Research and Design of the key Technologies of Power Management IC". A frequency adjustable and high efficient synchronous BUCK DC-DC converter XD2825 is designed.By studying and understanding the basic theory of analog CMOS integrated circuit design and combining with the market demand of current power supply equipment, the converter chip XD2825 adopts the peak current mode of PWM modulation mode to control the loop, which has a fast transient response speed.The conversion efficiency of the system is improved effectively by using synchronous rectification technology.In order to extend the application of the chip XD2825, the external synchronization module which can adjust the clock frequency is integrated in the system, so that the chip XD2825 can work in a wide range of clock frequencies.In order to make the system have higher conversion efficiency in the whole load range, the low power mode is integrated. The system can choose continuous mode or discontinuous mode according to the different load.This paper first introduces the research background, current situation and development of power management type integrated circuit, and the main performance index of switching power supply, and then analyzes the working principle of BUCK type DC-DC converter, including the topology structure of DC-DC converter.The main working mode, main modulation mode and main control mode provide the theoretical basis for the research and design of the chip XD2825 system-level, and then carry on the system-level research and design to the chip XD2825.The function of chip XD2825 and the specific electrical characteristic index are determined, and the whole function block diagram and each functional sub-module of the system are described in detail. Finally, the whole function of chip XD2825 is simulated to verify the effectiveness of its work.Then the layout design technology is briefly introduced, and the layout and overall layout of chip XD2825 are given.The chip XD2825 uses 0.5 渭 m BCD 30V manufacturing process, and the whole function is verified by the Spectre simulation tool under the Cadence simulation environment.The chip XD2825 will have a wide input voltage range of 4.75V~20V, an internal fixed clock frequency of 500kHz, an external synchronous clock frequency of 300KHz~2 MHz, a maximum load current of 4A, and a conversion efficiency of 95kHz.The chip can be widely used in routers, laptops, mobile power supply and other devices. It has the advantages of high conversion efficiency, low static power consumption and stable operation, which greatly improves the power performance of portable electronic devices.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM46

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