一种适用于便携式装置的LED背光恒流源驱动芯片设计
发布时间：2018-09-17 09:31
【摘要】：随着白光LED在1998年开发成功,白光LED给显示照明领域更带来了革命性的变化。白光LED具有无污染,长寿命,抗冲击,耐震动,节电和维护成本低等优点。在所有的LED应用设备中,便携式LED照明与显示装置是应用最为广泛的一类。因此LED背光驱动电路的研究成为一个越来越重要的课题。与传统的LED背光驱动不同,本文采用了恒流源驱动电路,使得芯片尺寸减小,成本下降。另外,本文设计的低压电流镜电路,实现了非常小的压降设计指标,大大降低了驱动电路的能量损耗,延长了应用装置的锂电池使用时间。本文首先介绍了系统的工作原理,给出了PWM控制方式实现的系统结构框图。然后本文一一阐述了各分模块的工作原理和电路设计,重点阐述了模拟电路部分的理论研究和设计实现,即基准电流源模块和电流镜电路模块。在基准电流源模块,论文介绍了几种典型的基准电压源电路,最后选择了Sub Bandgap结构的带隙基准电压源电路结构加以改进,作为为芯片的基准电流源。在电流镜电路模块中,论文设计的超低压降电流镜电路,相比较传统电流镜电路,具有更简单的电路结构和更小的压降。最后对整个芯片进行了前仿真和版图后仿真,仿真结果均达到或优于设计指标。
[Abstract]:With the successful development of white LED in 1998, white light LED has brought revolutionary changes to the field of display lighting. White LED has the advantages of no pollution, long life, shock resistance, vibration resistance, electricity saving and low maintenance cost. Among all LED applications, portable LED lighting and display devices are the most widely used. Therefore, the research of LED backlight drive circuit becomes more and more important. Different from the traditional LED backlight drive, the constant current source drive circuit is used in this paper, which reduces the chip size and reduces the cost. In addition, the low voltage current mirror circuit designed in this paper realizes the very small voltage drop design index, greatly reduces the energy loss of the drive circuit, and prolongs the life time of the lithium battery in the application device. In this paper, the working principle of the system is introduced, and the structure diagram of the PWM control mode is given. Then this paper describes the working principle and circuit design of each sub-module, focusing on the theoretical research and design of the analog circuit, that is, the reference current source module and the current mirror circuit module. In the reference current source module, several typical reference voltage source circuits are introduced in this paper. Finally, the bandgap voltage reference circuit with Sub Bandgap structure is selected to be the reference current source for the chip. In the current mirror circuit module, the design of ultra-low voltage drop current mirror circuit, compared with the traditional current mirror circuit, has a simpler circuit structure and smaller voltage drop. Finally, the whole chip is simulated before and after layout, and the simulation results reach or exceed the design target.
【学位授予单位】：复旦大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM923.34
本文编号：2245448
[Abstract]:With the successful development of white LED in 1998, white light LED has brought revolutionary changes to the field of display lighting. White LED has the advantages of no pollution, long life, shock resistance, vibration resistance, electricity saving and low maintenance cost. Among all LED applications, portable LED lighting and display devices are the most widely used. Therefore, the research of LED backlight drive circuit becomes more and more important. Different from the traditional LED backlight drive, the constant current source drive circuit is used in this paper, which reduces the chip size and reduces the cost. In addition, the low voltage current mirror circuit designed in this paper realizes the very small voltage drop design index, greatly reduces the energy loss of the drive circuit, and prolongs the life time of the lithium battery in the application device. In this paper, the working principle of the system is introduced, and the structure diagram of the PWM control mode is given. Then this paper describes the working principle and circuit design of each sub-module, focusing on the theoretical research and design of the analog circuit, that is, the reference current source module and the current mirror circuit module. In the reference current source module, several typical reference voltage source circuits are introduced in this paper. Finally, the bandgap voltage reference circuit with Sub Bandgap structure is selected to be the reference current source for the chip. In the current mirror circuit module, the design of ultra-low voltage drop current mirror circuit, compared with the traditional current mirror circuit, has a simpler circuit structure and smaller voltage drop. Finally, the whole chip is simulated before and after layout, and the simulation results reach or exceed the design target.
【学位授予单位】：复旦大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM923.34
【参考文献】
相关期刊论文 前1条
1 刘帘曦,杨银堂,朱樟明;基于MOSFET失配分析的低压高精度CMOS带隙基准源[J];西安电子科技大学学报;2005年03期
，本文编号：2245448
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