【作者】 吴玉强；

【导师】 吴玉广；

【作者基本信息】 西安电子科技大学 ， 微电子学与固体电子学， 2008， 硕士

【摘要】 目前,DC/DC转换器己在通讯、电子计算机、消费类电子产品等领域获得了广泛应用。为了提高其性能,高效率、高精度、高集成度成为设计的关键。本文首先介绍了降压型DC/DC转换器的工作原理,深入分析了转换器的各种功率损耗源和同步整流技术。然后对DC/DC转换器的关键电路进行了分析设计,包括:斜坡补偿电路、误差放大器/补偿网络、PWM比较器、电感电流检测电路、同步整流驱动电路、续流检测电路等。本文设计了结构新颖的内置电感电流检测电路和同步整流驱动电路,实现了电流模脉宽调制与同步整流技术的结合,有效地提高了DC/DC转换器的效率、精度和集成度。整个设计采用0.35um 3.3V CMOS模型,仿真结果显示,电源转换效率高达91%,稳态输出电压纹波为7mV,负载调整率为? 0.428(%/ A),线性调整率为,均达到或优于预定指标,满足高效率和高精度的要求。0.26(% / V)更多还原

【Abstract】 Recently, DC/DC switching converters have been widely used in communication systems, computers and consumer electronic products, etc. To improve the performance of DC/DC switching converters, high efficiency, high precision and high integration are the key in the design.Firstly, the basic principle buck DC/DC switching converter is introduced, and the various sources of power loss and the synchronous rectification technology are further analyzed. Then, the critical circuits are designed, including compensation ramp circuit, error amplifier/compensation network, PWM comparator, current-sensing circuit, synchronous rectification driving circuit and continuous-current sensing circuit, etc.a novel built-in current-sensing circuit and a synchronous rectification driving circuit are designed, thus the current-mode pulse-width modulation technology and the synchronous rectification technology are integrated skillfully. Consequently, the efficiency, precision and integration of the DC/DC converter are improved effectively.Based on the 0.35um 3.3V CMOS model, the whole circuit is simulated. The simulation result shows that the conversion efficiency is up to 91%, the output ripple voltage is only 7mV, the load regulation is ? 0.428(% / A) and the line regulation is 0.26(% / V). The specifications required are attained.更多还原