轻负载下BUCK电路的模式控制和分段技术研究与设计

发布时间：2018-11-07 21:49

【摘要】：在电子便携设备全面普及的今天,多媒体终端的发展,要求集成电路芯片朝着高集成度、更低功耗的方向发展,同时也对电源管理芯片提出了更高的要求,在有限的电池容量基础上,如何更好的延长电池使用时间,延长电池寿命成为重要课题。在众多电源管理芯片中,DC-DC变换器高效的特点使其得到更多的重视和更广泛的应用,因此,研究提高DC-DC变换器的系统转换效率是非常有意义的,本文正是致力于提高DC-DC变换器在全负载范围内都有较高的转换效率,对轻负载下Buck电路的模式控制和分段技术进行研究与设计。本文首先简述了当前DC-DC变换器的发展现状和趋势,以及开关电源的基本拓扑结构和常见调制模式,然后分析了轻负载下提升效率的两种方法。在此基础上,本文针对功率管的导通损耗和驱动损耗进行重点推导分析,作为本设计功率管分段的重要依据。本文详细描述了所设计的一款双模控制分段驱动功能的DC-DC变换器,重点设计了DCM下利用占空比检测电路量化负载电流,根据量化结果对功率管进行自适应分段,同时阐述了模式切换的设计和PSM调制模式具体电路等关键子电路的设计。最后优化电路参数,对整个DC-DC变换器的特征指标进行了细致的仿真验证,并完成了版图的设计。本文设计的芯片整体面积为1.2mm×1.25mm,采用0.13μm标准CMOS工艺,最终仿真结果显示本文设计的这款带有双模控制自适应分段的DC-DC变换器,能够在轻负载下通过模式切换和分段驱动技术有效的提高转换效率,全负载效率保持在70%以上,在15mA处通过分段效果,效率提升5.3%,验证了本次设计方案的可行性。
[Abstract]:With the popularity of electronic portable devices today, the development of multimedia terminals requires the development of integrated circuit chips towards the direction of high integration and lower power consumption. At the same time, it also puts forward higher requirements for power management chips. On the basis of limited battery capacity, how to prolong battery life and prolong battery life has become an important subject. In many power management chips, the high efficiency of DC-DC converter makes it get more attention and wider application. Therefore, it is very meaningful to study how to improve the system conversion efficiency of DC-DC converter. This paper is devoted to improving the conversion efficiency of DC-DC converters in the full load range. The mode control and segmentation techniques of Buck circuits under light load are studied and designed. In this paper, the current development and trend of DC-DC converters, the basic topology and common modulation modes of switching power supply are briefly introduced, and then two methods of improving efficiency under light load are analyzed. On this basis, this paper focuses on the derivation and analysis of the conduction loss and drive loss of the power transistor, which is an important basis for the design of the power tube segment. In this paper, a novel DC-DC converter with two-mode control is described in detail. The duty cycle detection circuit is used to quantify the load current in DCM. According to the quantization results, the power transistor is segmented adaptively. At the same time, the design of mode switching and key sub-circuits such as PSM modulation mode circuit are described. Finally, the circuit parameters are optimized and the characteristic indexes of the whole DC-DC converter are simulated and verified in detail, and the layout is designed. The overall area of the chip is 1.2mm 脳 1.25mm, and the 0.13 渭 m standard CMOS technology is used. The simulation results show that the designed DC-DC converter has dual-mode control adaptive segment. It can effectively improve the conversion efficiency by mode switching and segmented driving under light load. The full load efficiency is kept above 70%, and the efficiency is improved by 5.3% at 15mA, which verifies the feasibility of the design scheme.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM46

【共引文献】