一种同步Boost转换器芯片的研究与设计

发布时间：2018-08-13 21:42

【摘要】：开关电源型DC-DC转换芯片由于具有拓扑结构灵活、转换效率高、应用范围广和可集成度高等优点被广泛运用于各类便携式电子产品的电源管理单元（PMU）中。随着白光LED照明、移动电源和智能锂电池充电器的迅速发展，升压型（Boost）DC-DC转换器芯片作为这些产品中必不可少的部分，已成为近年来集成电路行业的研究热点之一。针对单节锂电池充电器，本文采用SMIC0.18μm工艺设计了一款峰值电流模式Boost转换器芯片，其输入电压范围为1.8V~3.3V，输出电压稳定于4V，负载电流范围为200mA~600mA，系统开关频率为1MHz。在设计过程中，提出了一种新型电流检测电路，实现了高精度、镜像管低匹配误差和低功耗的电感电流检测；同时，提出了一种带有吉尔伯特单元的斜波补偿电路，有效地消除了电流模式容易出现的次谐波振荡现象。仿真结果表明，，所设计的Boost转换器芯片的最高转换效率高达92%，且平均瞬态响应时间为48.7μs，最大输出电压纹波为72mV，因此具有瞬态响应快和纹波系数低等特点。文中首先介绍了DC-DC转换器的常用拓扑结构、调制方式和反馈机制，然后详细推导了Boost拓扑结构在连续导通模式（CCM）和断续导通模式（DCM）下的常用电学表达式，之后从外围元件的选择、电流检测方案分析和基于Matlab环路稳定性分析三个方面介绍了系统设计思路，接着基于Cadence Spectre完成芯片各模块的电路设计和仿真验证，最后在实际工作条件下进行系统仿真并得出结论。
[Abstract]:Switching power supply (DC-DC) converter is widely used in the power management unit (PMU) of portable electronic products because of its advantages of flexible topology, high conversion efficiency, wide application range and high integration. With the rapid development of white LED lighting, mobile power supply and intelligent lithium battery charger, booster (Boost) DC-DC converter chip, as an essential part of these products, has become one of the research hotspots in integrated circuit industry in recent years. For a single lithium battery charger, a peak current mode Boost converter is designed using SMIC0.18 渭 m technology. The input voltage range is 1.8 V / L 3.3V, the output voltage is stable at 4V, the load current range is 200mAn 600mA, and the switching frequency of the system is 1MHz. In the process of design, a novel current detection circuit is proposed, which can detect inductance current with high precision, low matching error and low power consumption. At the same time, an oblique wave compensation circuit with Gilbert cell is proposed. The phenomenon of subharmonic oscillation which is easy to occur in current mode is effectively eliminated. The simulation results show that the maximum conversion efficiency of the designed Boost converter is as high as 92um, the average transient response time is 48.7 渭 s, the maximum output voltage ripple is 72 MV, so it has the characteristics of fast transient response and low ripple coefficient. In this paper, the common topology, modulation mode and feedback mechanism of DC-DC converter are introduced, then the electrical expressions of Boost topology under continuous on-mode (CCM) and intermittent on-mode (DCM) are derived in detail. Then the system design ideas are introduced from three aspects: the selection of peripheral components, the analysis of current detection scheme and the stability analysis based on Matlab loop. Then the circuit design and simulation verification of each module of the chip are completed based on Cadence Spectre. Finally, the system simulation is carried out under the actual working conditions and the conclusion is drawn.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM46

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