一种异相双输出同步整流BUCK型DC-DC控制器设计与研究

发布时间：2018-04-13 10:22

  本文选题：同步整流 + 斜坡补偿　； 参考：《电子科技大学》2014年硕士论文

【摘要】：便携式电子设备朝低压低功耗方向发展,CPU、MCU等数字处理器的集成度及工作频率越来越高,需要电源对其供电的电流也越来越大。这就需要电源系统具有提供大电流和低输出电压能力。文章介绍了一种具有异相时钟控制双输出通道、工作频率可变(140KHz-650KHz)、内部设定可以选择工作频率(250KHz、400KHz、600KHz)、输入电压范围为4-40V、输出电压范围为0.8-10V、重载时电源转换效率达到90%以上、具有良好线性调整率和负载调整率、能够适用于大电流输出的应用环境、使用电流模式PWM控制技术使输入输出电压突变可得到快速响应的同步整流BUCK型DC-DC转换器芯片设计。设计上采用自上而下的设计方法,结合理论分析,从芯片整体架构出发,阐明双通道转换器的架构及工作原理,并说明了采用此架构的优缺点;接下来对具体通道的PWM环路控制方法进行对比论证,提出优化设计方案,并分析此优化方案的环路补偿方法;之后设计了PWM环路相关电路模块:误差放大器、PWM比较器、斜坡补偿电路、振荡器等,并对各个电路模块仿真数据进行分析验证;最后,对芯片外围架构及外围主要器件的选择进行分析,并在此基础上对芯片整体系统仿真数据进行分析,给出一些主要系统参数的仿真数据。整体系统仿真数据显示,所设计的DC-DC转换器在输出电压为3.3V、输出电流5A和输出电压为8.5V、输出电流3.5A条件下,各项仿真参数都满足设计要求。
[Abstract]:Portable electronic devices are developing towards low voltage and low power consumption. The integration and working frequency of digital processors such as CPU / MCU are becoming higher and higher.This requires the ability of the power system to provide high current and low output voltage.It has good linear adjustment rate and load adjustment rate, and can be used in the application environment of high current output. The design of synchronous rectifier BUCK type DC-DC converter chip can be obtained by using current-mode PWM control technology to make the input and output voltage abrupt change to obtain fast response.In the design, the top-down design method is adopted, combined with the theoretical analysis, the architecture and working principle of the dual-channel converter are expounded from the overall architecture of the chip, and the advantages and disadvantages of using this architecture are explained.Then the PWM loop control method of the specific channel is compared and demonstrated, and the optimal design scheme is put forward, and the loop compensation method of the optimization scheme is analyzed. Then, the relative circuit module of the PWM loop is designed: error amplifier and PWM comparator.The ramp compensation circuit, oscillator, etc., and the simulation data of each circuit module are analyzed and verified. Finally, the selection of the peripheral architecture and main peripheral devices of the chip is analyzed.On this basis, the simulation data of the whole chip system are analyzed, and the simulation data of some main system parameters are given.The whole system simulation data show that the designed DC-DC converter meets the design requirements at output voltage of 3.3 V, output current of 5A and output voltage of 8.5 V, and output current of 3.5A.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM46
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本文编号：1744079