在便携式全球移动通信系统中的低功耗AMOLED显示(英文)

Powering Small AMOLED Display in Portable GSM Systems

被动矩阵OLEDs已有许多应用,流行于如移动电话,汽车仪表板里等。与LCD-TFT相比,OLED技术有宽视角,高对比度,反映时间快和消除背光功率消耗的优点。然而被动矩阵的局限是显示尺寸,使得这项科技在显示大于1.5inch时不合适。主动矩阵OLED技术是一个正在兴起的技术,他可以改变显示世界的形势。他能结合PM技术的优势,简单地战胜尺寸局限而且现在已经被大规模投入生产了。然而,AMOLED显示为工程师们提出了新的挑战。实际上AMOLED驱动需要提供供电正极和负极的锂电池电源。因此由一个推进器和变极器制成的双DC/DC转换器要求有高度信号完整来驱动稳定电压。实际上为了避免显示时色彩漂移和显示闪烁,DC/DC转换器的开关必需与一些有挑战性的相联系特性如高精确度和很好的动态参数。便携式应用的关键特性是考虑了包括保留电池生命期,部件处理和非常合适的外型方案。回顾便携式全球移动通信系统在AMOLED显示应用中的来自动力供应方向的挑战,在讨论了不同的约束条件下给出了一个有效的系统设计方案。

Passive Matrix OLEDs are now popular in many applications such as mobile phones, mainly for the sub display in clam shell or in automotive for dashboard. Compared to ICD-TFT, OLED technology has great advantage of wider viewing angle, higher contras ratio, very quick response time and elimination of the backlight power consumption. However the main limitation of Passive Matrix is the display size, making this technology not suitable for display larger than 1.5 inch. Active Matrix OLED technology is an emerging technology that will change the display world situation. It can associate PM technology advantages, easily overcomes this limitation and is now ready for mass production. However, AMOLED display raises new challenges for engineers. In fact the AMOLED driver requires a positive and negative power supply from a Li-Ion battery. Therefore a dual DC/DC converter made up of a boost plus an inverter is required to deliver regulated voltage with high signal integrity. Actually to avoid any color shift and flicker on the display the DC/DC converter must combine challenging features such as high accuracy and excellent dynamic parameters. Also key features for portable application are taking into account including preserving battery life time, parts count and very low profile solution. This paper reviews the challenge of powering AMOLED display for portable application and after discussing the various constraints requirements gives an efficient solution to the system designer.