一种高效率宽输出电压范围的降压型DC-DC转换器设计

发布时间：2018-01-03 06:02

本文关键词：一种高效率宽输出电压范围的降压型DC-DC转换器设计　出处：《西安电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着IC技术产业的快速发展,便携式电子产品日益普及,智能设备也正在蓬勃发展,如笔记本电脑、智能手机、智能电视、车载导航、行车记录仪等,也将在未来成为主流,这些都将成为工作生活中越来越重要的工具。结合其自身产品各自的特点,如笔记本电脑的便携性,智能手机的电池稳定和持久耐用性等等,使得其对电池寿命的要求越来越高。因此,对开关电源的需求更大且性能要求更高,如效率要求更高,功耗更低,驱动能力和耐压能力更强等。因此本文设计一个高效率宽输入范围Buck型DC-DC转换器[2]。首先分析了基本的Buck型DC-DC的基本原理,反馈控制模式的特点,随后对开关电源设计中的关键技术进行了阐述,如减小功耗的同步整流技术、保证环路稳定性的环路补偿技术、提高效率的工作模式切换技术等等。最终根据应用需求确定了本设计中的DC-DC转换器将采用峰值电流模控制方式并随后对整个芯片系统中各个功能模块进行了原理性分析和设计,如电压环路中的误差放大器、PWM比较器;电流环路的电流放大器和斜坡补偿电路;振荡器、带隙基准等。同时对各个功能模块进行了详细的原理性分析。最后基于0.35μm BCD-MOS工艺[4],使用Spectre仿真工具对整个Buck型DC-DC转换器进行了模块仿真和系统级仿真验证。仿真结果表明,本论文中设计的开关电源的输入电压为4.5V~16V,输出电压为1.8V~(Vin-3)V,最大负载电流为3A,典型负载电流1A,振荡器频率为1MHz。实现了大的输出电压范围,同时在效率上最大可达到94%。Buck型DC-DC转换器在轻载情况下会工作在DCM模式,提高效率;芯片会在重载情况下切换到打嗝(Hiccup)工作模式,防止大电流损坏整个芯片系统的同时提高效率。为了进一步提高效率,整个系统中通过增加死区时间控制电路来减小导通损耗,零电流比较器来防止电流倒灌引起的损耗。整个芯片最后加了过温保护、过流保护和欠压锁定等保护模块来保证芯片正常安全工作。
[Abstract]:With the rapid development of IC technology industry, portable electronic products are becoming more and more popular, and smart devices are booming, such as notebook computer, smart phone, smart TV, vehicle navigation, CarLog and so on. They will also become mainstream in the future, which will become increasingly important tools in working life, combining the characteristics of their own products, such as the portability of laptops. The battery stability and durability of smart phone make the demand for battery life more and more high. Therefore, the demand for switching power supply is greater and higher performance requirements, such as higher efficiency requirements, lower power consumption. Therefore, a high efficiency and wide input range Buck type DC-DC converter is designed in this paper. [2]. Firstly, the basic principle of Buck type DC-DC and the characteristics of feedback control mode are analyzed, and then the key technologies in the design of switching power supply are described. Such as reducing power consumption of synchronous rectifier technology, loop compensation technology to ensure the stability of the loop. Finally, according to the application requirements, the DC-DC converter in this design will adopt peak current mode control mode, and then the whole chip system each function module into. Principle analysis and design are carried out. Such as voltage loop in the error amplifier PWM comparator; Current amplifier and ramp compensation circuit of current loop; Oscillator, bandgap reference, etc. At the same time, the principle of each functional module is analyzed in detail. Finally, based on 0. 35 渭 m BCD-MOS process. [4. The module simulation and system-level simulation of the whole Buck type DC-DC converter are carried out by using the Spectre simulation tool. The simulation results show that. The input voltage, output voltage and maximum load current of the switching power supply are 4.5V, 16V, 1.8 V and 3A, respectively, and the typical load current is 1A. The oscillator frequency is 1MHz. The output voltage range is large, and the maximum efficiency of 94. Buck DC-DC converter will work in DCM mode under light load. Improving efficiency; The chip will switch to hiccup cupboard working mode under heavy load to prevent high current damage to the entire chip system while improving efficiency in order to further improve efficiency. In the whole system, the on-loss is reduced by adding dead-time control circuit, and the zero-current comparator is used to prevent the loss caused by current inversion. Finally, the whole chip is protected by over-temperature. Protection modules such as overcurrent protection and undervoltage locking are used to ensure the safe operation of the chip.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM46

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