基于可变斜率补偿的LED驱动芯片的研究与设计

发布时间：2018-01-15 02:33

本文关键词：基于可变斜率补偿的LED驱动芯片的研究与设计　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：结合目前集成电路制造技术,计算机辅助设计,半导体材料的先进研究成果,LED照明成为目前集成电路产业中一个重要的发展方向。随着LED照明技术发展,LED电源是实现LED照明优势的核心模块,而作为LED电源模块中的核心模块——驱动芯片则是决定驱动电源性能。因此,本论文致力于驱动芯片的研究与设计。论文结合半导体照明的背景,并且阐述在LED照明中驱动电源和驱动IC的作用。同时本论文在对非隔离型的DC-DC模式的驱动芯片的原理介绍的基础上,研究和分析了非隔离型DC-DC模式的驱动芯片的整体结构的工作原理,驱动控制方式,反馈控制模式,系统稳定和斜坡电压补偿的原理和方法。在固定斜坡补偿技术上设计出可变斜率斜坡电压补偿的升压型驱动芯片,此可变斜率斜坡补偿技术通过采样芯片的输入电源电压信号和LED负载端电压信号。并将采样信号通过V-I电路,成为电流输出。同时结合脉冲信号控制电容的充放电流的原理,利用芯片内的OSC模块产生的脉冲信号控制采样输入和输出转换的电流对电容的充放电,从而产生和输入、输出电压线性相关的斜坡电压,从而得到和输入以及输出电压线性相关的斜率,通过将斜坡电容产生的不同斜率的斜坡电压反馈到驱动芯片内部的PWM比较器进行比较得到PWM脉冲信号,从而实现本论文设计的芯片能够输出恒流,驱动LED芯片。论文设计的芯片内部还包括电压带隙基准源,低压差线性稳压源,振荡器,过压保护,欠压保护等模块,用以保证芯片能够实现基本功能以及本论文设计的可变斜率补偿技术。芯片的电路设计采用CSMC 0.5μm BCD工艺的BJT,中压MOSFET来设计芯片内部的子模块电路,以及电路的版图设计。并且对子模块电路和芯片全局电路的功能进行仿真,验证。芯片在输入6V至10V时,输出电压为18V,输出峰值电流可高达350mA。同时芯片的电压输出精度高于3%,输出电流精度高于10%。芯片在较大的占空比脉冲控制信号下,输出功率变化率仅为3.1%,实现了较大占空比变化下可变斜坡补偿技术能够最大限度保持芯片的带负载能力。
[Abstract]:Combined with the current integrated circuit manufacturing technology, computer aided design, semiconductor materials advanced research results. LED lighting has become an important development direction in the IC industry. With the development of LED lighting technology, LED power supply is the core module to realize the advantages of LED lighting. As the core of the LED power module, the driver chip determines the performance of the driving power supply. Therefore, this paper is devoted to the research and design of the driver chip. At the same time, this paper introduces the principle of non-isolated DC-DC mode driver chip. The working principle, driving control mode and feedback control mode of the drive chip of non-isolated DC-DC mode are studied and analyzed. The principle and method of system stability and slope voltage compensation. A boost drive chip with variable slope slope voltage compensation is designed in the fixed slope compensation technology. The variable slope slope compensation technique passes the input power supply voltage signal of the sampling chip and the LED load terminal voltage signal, and the sampling signal is passed through the V-I circuit. At the same time, combined with the principle of pulse signal to control the charge and discharge of the capacitor, the pulse signal generated by the OSC module in the chip is used to control the charge and discharge of the capacitance from the sampling input and the output converted current. Thus the slope voltage linearly related to the input and output voltage is generated and the slope linearly related to the input and output voltage is obtained. The slope voltage of different slope produced by the ramp capacitance is fed back to the PWM comparator inside the driver chip to get the PWM pulse signal, so that the chip designed in this paper can output constant current. Driving LED chip. The chip also includes voltage bandgap reference source, low voltage difference linear stabilizer source, oscillator, over-voltage protection, under-voltage protection and other modules. In order to ensure that the chip can realize the basic functions and the variable slope compensation technology designed in this paper, the circuit design of the chip adopts BJT of CSMC 0.5 渭 m BCD technology. The middle voltage MOSFET is used to design the sub-module circuit and the layout of the circuit. The function of the sub-module circuit and the global circuit of the chip is simulated. Verification. The output voltage of the chip is 18V when the input voltage is 6V to 10V, and the output peak current can be up to 350 Ma. At the same time, the output precision of the chip is higher than 3%. The output current accuracy is higher than 10. The output power change rate of the chip is only 3.1% under the larger duty cycle pulse control signal. The variable slope compensation technology with large duty cycle can maximize the load capacity of the chip.
【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】：TM923.34

【相似文献】