【作者】 胡佳民；

【导师】 王松林；

【作者基本信息】 西安电子科技大学 ， 电路与系统， 2009， 硕士

【摘要】 本论文设计工作来源于西安电子科技大学电路CAD研究所的科研项目“深亚微米电源管理类集成电路的关键技术理论研究与设计”,主要对Buck型DC-DC稳压器的设计和相关理论进行了研究,并在此基础上设计实现了一款适用于便携系统的高效电流模Buck型DC-DC稳压器XD1106。芯片基于0.5μm标准CMOS工艺模型,使用Cadence、Hspice等EDA工具仿真验证,整体电路设计已完成,各项指标均达到设计要求。XD1106采用同步整流技术和轻负载下可切换到LDO的工作模式,提高了全负载范围内的工作效率;设计该芯片在输入电压降低至接近输出电压时,主开关管100%占空比导通工作,以延长电池的使用寿命。芯片采用峰值电流模式脉宽调制控制方案,大大提高了芯片电源电压和负载变化的瞬态响应性能,并设计了分段线性斜坡补偿电路以消除电流环路的不稳定性。同时设计可根据斜坡补偿信号幅度进行阈值自调节的箝位电路,消除了斜坡补偿对芯片带载能力的影响。在对电压环路的稳定性进行分析的基础上,利用内部频率补偿实现了稳定性设计。另外,芯片还集成了过压保护、过温保护等多种保护电路,确保系统更加安全和稳定。更多还原

【Abstract】 Supported by the research project of Institute of Electronic CAD-“Theoretical research and design of key techniques for deep-submicron power management IC”, this paper analyzes the design and related theory of Buck DC-DC regulator in detail. And a high efficiency current mode Buck DC-DC regulator XD1106 for portable applications is designed. The whole chip is designed in 0.5μm standard CMOS process, simulated with Cadence and Hspice simulation tool, the simulation results show that all specifications are met.By adopting the technologies of synchronous rectification and LDO mode at light loads, the efficiency of the chip is enhanced at whole load range.To further maximize battery life, when input supply voltage decreases towards output voltage, the duty cycle increases to 100%, which is the dropout condition, and the PMOS switch is turned on continuously. As a result of the adoption of peak current mode PWM control, the transient response speed of the supply voltage and the load’s variety becomes much faster. In order to avoid the current loop instability, a new piecewise linear slope compensation circuit is designed. A clamp circuit whose threshold can be adjusted with respect to the magnitude of the slope compensation signal is also designed to cancel the slope compensation effect on current limit. Based on analysis of voltage loop frequency compensation, stability is realized through internal compensation. Over voltage protection circuit, over temperature protection circuit and other protection circuits are designed, which make the system more reliable and stable.更多还原