LTPS TFT电流模型在AMOLED像素电路中的应用

发布时间：2018-04-23 18:36

本文选题：低温多晶硅薄膜晶体管 + 电流模型　；参考：《苏州大学》2015年硕士论文

【摘要】：本文综合地研究LTPS TFT的电流模型,在前人的基础上对部分模型进行优化,如对亚阈值电流输出特性的关注。通过实验观测,我们发现在亚阈值区中也存在一个饱和电压,该电压点主要受载流子的速度饱和效应影响。本文还将所有区域的电流模型整合起来,以便于模型的实际应用。将开态电流模型应用于分析最基础的AMOLED像素驱动电路——2T1C像素电路中。我们可以明确的计算出像素电路的充电时间、驱动电流,估算器件的退化效应和由寄生电容引起的电荷注入效应、时钟馈通效应对驱动电流的影响。开态电流模型的参数物理意义明确,且数目较少。该模型可用于电路设计的初步预估,即在已知的驱动模式下,通过该方法我们就可以判断LTPS TFT器件是否能够满足驱动的需求。我们将LTPS TFT的电流模型应用于仿真软件中,自动化地分析和设计电路。首先,我们用Verilog-A语言正确的描述出LTPS TFT的电流和电压行为,再使用与Verilog-A兼容的Hspice仿真器,分析像素电路特性。我们选用较为典型的电压驱动型像素电路和电流驱动型电路各一组来进行示范。直流分析,选定恰当的电路工作点;瞬态仿真,观察电路中各个节点的动态响应,模拟像素电路的实际工作情况。经过优化提高的器件电流模型完全可以应用于实际生产。
[Abstract]:In this paper, the current model of LTPS TFT is studied synthetically, and some of the models are optimized on the basis of previous studies, such as the attention to the subthreshold current output characteristics. It is found that there is also a saturation voltage in the sub-threshold region, which is mainly affected by the carrier velocity saturation effect. In this paper, the current models in all regions are integrated to facilitate the practical application of the model. The open state current model is applied to the basic AMOLED pixel drive circuit 2T 1C pixel circuit. We can calculate the charging time, the driving current, the degradation effect of the device, the charge injection effect caused by the parasitic capacitance, and the effect of the clock feedthrough effect on the driving current. The physical meaning of the open current model is clear and the number is small. This model can be applied to the preliminary prediction of circuit design, that is, under the known driving mode, we can judge whether the LTPS TFT device can meet the driving requirements by this method. The current model of LTPS TFT is applied to the simulation software, and the circuit is analyzed and designed automatically. First, we describe the current and voltage behavior of LTPS TFT correctly with Verilog-A language, and then use Hspice simulator compatible with Verilog-A to analyze the characteristics of pixel circuits. We choose typical voltage-driven pixel circuit and current-driven circuit to demonstrate. DC analysis, select the appropriate circuit operating point, transient simulation, observe the dynamic response of each node in the circuit, simulate the actual work of pixel circuit. The improved device current model can be used in practical production.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN383.1

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