【作者】 朱志甫；

【导师】 白天蕊；

【作者基本信息】 西南交通大学 ， 微电子学与固体电子学， 2008， 硕士

【摘要】 作为电源管理芯片中的核心部分,PWM(Pulse Width Modulation)比较器需要具有高增益和适当的带宽、小的失调电压、在低功耗情况下具有较短的响应时间。本论文在分析研究现有开关电源PWM控制模式基础上,根据PWM比较器的电路结构,设计了一种应用在DC-DC开关电源控制芯片中的高性能PWM比较器。该比较器结构简单、增益高、失调电压和延时都很小、功耗低。第一章对PWM开关电源发展、论文选题背景、本论文要做主要工作进行了介绍。第二章在分析PWM原理基础上,画出了SPICE等效模型,并给出了网表和模拟仿真结果。对开关电源的调制模式和反馈控制模式进行了分析研究。第三章分析PWM比较器的性能参数并列举了几种常见比较器结构,分析了电路原理。第四章,根据设计比较器的性能指标,利用基本CMOS模拟子电路功能,详细分析PWM比较器各个子模块,并给出了PWM比较器整体电路。第五章通过在上华0.5umCMOS工艺下采用Cadence Spectre软件对本论文设计PWM比较器性能指标进行模拟仿真和分析。仿真结果表明,达到了设计要求。在电源电压5V,温度为27℃的情况下,增益为104dB,-3dB带宽144Khz,失调电压为444uV,上升时延为99ns,下降时延为60ns,静态功耗仅530uW。通过与文献中设计的PWM比较器性能参数进行比较,得出本论文设计PWM比较器模块优点及不足。最后,在结论中指出了本论文设计的意义及不足,还需完成版图设计后仿真等工作。更多还原

【Abstract】 As a core of the power management chip, PWM comparator must have high gain, suitable bandwidth and small offset voltage. At the same time,it must have a low power dissipation and a short response time. So, the key of designing this kind of comparator is keeping a tradeoff among all parameters of it. Based on the analysis and comparison of modulation and control modes of PWM SMPS (SWITCHED-MODE POWER SUPPLY) , a high performance PWM comparator applied in DC-DC SMPS power management is presented. This novel PWM comparator is simple in structure, high gain, small offset voltage and response time and low power.In the first chapter, the paper mainly introduced the PWM SMPS of development, background papers topics and its to be done. In the second chapter of this pape,we analysis the principle of PWM, draw the equivalent SPCIE model,and gives the netlist and the simulation results. And analysis the PWM SMPS control principle. In the 3rd chapter, we analysis PWM comparator of the paramenters and Performances, and enumerate some kinds of comparator and analysis their circuit principle. From the beginning of the fourth chapter, according to comparator the performance of the design indicators, and we are used of the basic CMOS analog circuits and analysis this paper applies to the SMPS PWM comparator in the various modules. And the all circuits of PWM comparator is be drawed. In the fifth chapter of this paper, we give the simulation results in detail in ShangHua 0.5um CMOS technologies through CADENCE SPECTRE Software. Simulation results shows that the required function of PWM comparator have be realized and reached our aim. We has got a result that the gain is 104.4dB, the bandwidth is 145KHz in -3dB gain, the offset voltage is 444uv, the arise response time is 99ns, the down response time is 60ns, and the power dissipation is 530uW. Then we get the advantages and shortcomings of our PWM comparator by compared with other comparators.Finally, in conclusion we point out the meaning and shortages of this design and some work such as LAYOUT needing to do in future.更多还原