【作者】 张玺；

【导师】 应建华；

【作者基本信息】 华中科技大学 ， 电子科学与技术， 2006， 硕士

【摘要】 高效率DC-DC转换器可以延长手持装置用电池寿命。本文结合工程项目设计了一种高效率DC-DC转换器。其特点是可用于数码产品、手机等便携式的电子设备,把电池提供的低电压经过开关变换提高到所需的较高电压。本课题从DC-DC转换器的升压型拓扑结构出发,对转换器的脉宽调制方式作了详细的阐述和探讨。分析其优缺点和改进措施,并给出相应的解决方案。论文根据便携式设备对体积、成本和功耗的严格要求,设计了转换芯片的体系结构。主要特点有:把功率开关管集成到芯片内部,开关管的开关频率高达1.2MHz,外部电容电感等常规大体积的元件可以选用小容量的表面贴装器件,极大的减小了电源系统的体积;为了减小电子设备的待机功耗,进一步提高电池的利用效率,本电源芯片设计采用了电流模式加脉宽调制的工作方式。电流模式保证了较好的动态响应和较高的灵敏度,调节性能好,减小了输出电压的波动。对关键电路进行了Spectre模拟验证,同时根据工作模式选择合适的外部元件对系统进行模拟,并给出模拟结果和结果分析。模拟结果证明该转换器满足了不同负载下高效率的设计要求。更多还原

【Abstract】 Motivated by emerging portable applications that demand low-power hardware to maximize battery run-time, high-efficiency low-voltage DC-DC conversion is a better selection. The thesis is a conclusion of a high efficient DC-DC converter design.This thesis discussed the pulse width modulation (PWM) control of a boost DC-DC conversion. Analysis the advantages and disadvantages about the PWM control technologies, and provide a solution.According to the strict request for the bulk, cost and power, the architecture of the converter is designed. The following is the main characteristics of the converter: With high switching frequency at 1.2MHz, and with the integration of the switch transistor and the PWM controller into one chip, SMT (Surface mounting technology) capacitor & inductor can be applied to minimize the bulk of the power supply system; Advanced Current Mode circuit are specially used to ensure lower power consuming, better transient response and less fluctuate of output voltage.Simulate all critical functional blocks and give results with Spectre. Select different components, simulate the system and give the results about system characters. The result showed the efficiency at the variable loads.更多还原