一种基于带隙基准源的AMOLED显示面板温度补偿系统设计

发布时间：2018-06-23 15:15

  本文选题：OLED + 温度补偿结构　； 参考：《电子科技大学》2014年硕士论文

【摘要】：近几年AMOLED显示屏幕因其表现出比LCD显示器具有更广的视角、更好的画质、更快的响应速度,但是又不需要背光板,而且功耗更低等优点而被广泛应用于移动终端,尤其AMOLED的柔性特点可以使其有更加广泛的应用领域。据displayresearch近年来的调研报告显示,OLED的渗透率逐年攀升,大有取代LCD成为新一代主流显示屏的趋势。OLED器件随温度的降低会出现发光亮度衰减和启亮延迟等问题,因此为了保持优质的显示效果,设计一个能够补偿OLED这种温度特性的系统是有意义的。本论文设计了一种用于补偿OLED因温度降低而造成的发光亮度衰减和启亮延迟的电路结构,该结构主要包括用于检测显示面板温度的传感器电路和用调节电压方式补偿OLED亮度变化的补偿电路的一部分,也设计了将传感器输出转化为对补偿电路控制信号的数字转换电路。区别于市面上通过驱动芯片来检测温度并输出控制信号来调整AMOLED负电源电压值的方式,本设计将完全集成于显示驱动芯片上,采用调整片上基准输出电压进而完成对GAMMA曲线调整的方式来进行补偿,不用芯片互联和增加输出引脚。在本设计中,因为补偿范围是从-30℃到10℃之间,且每隔10℃补偿一次,因此对传感器精度并不严苛,折衷面积和功耗的要求设计了一款频率输出的传感器,传感器输出频率随温度成线性增大,相邻两摄氏度的频率差约为117kHz,精度为1℃,功耗约为152μW;信号转换电路由一个9位计数器和由若干与门、与非门和D触发器组成,通过设置相应的计数阈值(约8.5μs)而得到相应温度下的频率计数,进而将计数转换为控制电平;补偿电路结构是对芯片系统中的带隙基准源进行改进,使基准源的输出电压可调,总共6个不同非等差数列的电压输出值,补偿不同的温度条件。基准的温度系数为10ppm/℃,PSRR为-75.4dB,误差±2.3mV以内。通过仿真验证表明设计出来的电路系统可以实现预期的功能。
[Abstract]:In recent years, the AMOLED display screen has been widely used in mobile terminals because of its advantages such as wider viewing angle, better picture quality, faster response speed than LCD display, but no need of backlight board, and lower power consumption. In particular, the flexibility of AMOLED can make it have a wider range of applications. According to the research report of displayresearch in recent years, the penetration rate of displayresearch has been increasing year by year, and it has a tendency to replace LCD as a new generation of mainstream display screen. With the decrease of temperature, OLED devices will have the problems of luminance attenuation and brightness delay, etc. So it makes sense to design a system that can compensate for the temperature characteristics of OLED in order to maintain good display effect. In this paper, a circuit structure is designed to compensate for the luminance attenuation and delay caused by the temperature decrease of OLED. The structure consists mainly of a sensor circuit for detecting the panel temperature and a part of a compensation circuit for compensating the brightness change of OLED by regulating the voltage. A digital conversion circuit is also designed to convert the sensor output to the control signal of the compensation circuit. Different from the way in the market where AMOLED negative power supply voltage can be adjusted by driving chip to detect temperature and output control signal, this design will be fully integrated into display driver chip. The method of adjusting the output voltage of on-chip datum to adjust the gamma curve is adopted to compensate without the chip interconnection and the increase of output pin. In this design, because the compensation range is from -30 鈩，

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