【作者】 郭仲杰；

【导师】 来新泉；

【作者基本信息】 西安电子科技大学 ， 电路与系统， 2007， 硕士

【摘要】 本论文的设计工作来源于西安电子科技大学的科研项目“电源管理类集成电路关键技术理论研究与设计”，作者承担了一款高效率、大电流、输出可动态调节DC／DC集成电路的研究与设计工作。 论文在深入系统地分析和研究了电流模降压型DC／DC转换器的工作原理和关键技术的基础上，成功地设计了一款高效率、大电流、输出可动态调节DC／DC转换器芯片XD6927。该芯片的转换效率可高达96％，采用同步整流技术，提高芯片转换效率的同时节省了PCB板的面积：突发工作模式的引入使得芯片在轻负载条件下仍然能够保持高效率；内置旁路PMOS管的设计减小了总的导通电阻，降低了电感上的功率损耗，提高了芯片的转换效率。XD6927采用新颖的分段线性斜坡补偿技术，解决了在大占空比条件下电流环路不稳定的问题，避免了在小占空比条件下过补偿现象的发生，提高了系统的带载能力。XD6927引入外部基准引脚REF，在外部调节器的驱动下，轻松地实现了输出电压在0.3V～3.5V的范围内动态可调节。最后，为了解决芯片的可测性问题，通过管脚复用设计了相应的测试电路，可缩短芯片的研发周期以及提高产品的效益。 文中对XD6927的系统及主要功能模块进行了详细的理论分析，并基于0.5μm CMOS工艺，利用Workview、Hspice等EDA软件完成了电路的设计和前仿真验证，仿真结果表明各项性能指标满足设计要求。更多还原

【Abstract】 Based on the project of "Theoretical Research and Design of Key Techniques for Power Management IC", a dynamic output DC/DC converter IC characterized by high efficiency and high current is designed in this paper.A dynamic output DC/DC converter IC XD6927 characterized by high efficiency and high current is designed to perform this function after an in-depth systemic study on the fundamental principles and key techniques employed in current-mode Buck converter. The efficiency of this design can be as high as 96% by adopting the technologies of synchronous rectification, dual operation modes and bypass P-channel FET. A novel slope compensation scheme is introduced into XD6927 to provide stability by preventing the sub-harmonic oscillations at high duty cycles and avoid the occurrence of over compensation at low duty cycles, improve the loading capacity of the system. XD6927 provides DC/DC conversion from single lithium-ion cell voltages down to a dynamic output 0.3V～3.5V, which can be easily modulated by driving the REF pin. Finally, to solve the test of the chip, the relevant test circuit is designed by the muti-function of the pad, which can shorten the research cycle and improve the benefit of the chip.Detailed theoretical analysis of system and main sub-blocks of XD6927 are made in the paper and based on 0.5μm CMOS process, the schematic design, pre-layout simulations and verifications have been completed using the EDA tools of Workview and Hspice. The simulation results turn out to be that all the functions have been implemented and electrical characteristics are consistent with the design specification.更多还原