Chapter 12
High-Speed Current-Mode Data Drivers for Amoled Displays
12.1 Introduction
It is generally known that active matrix organic LED (AMOLED) displays have several advantages over other display technologies in the flat-panel display industry. Among these advantages are their light and thin form factors and wide viewing angle due to self-emission, faster response time leading to lower motion artifacts, wide color gamut in all gray scales, and low power consumption due to the elimination of backlight units. In addition, AMOLED displays can reduce their power consumption owing to their higher contrast ratio and the wider color gamut in comparison with LCDs because AMOLED displays are perceived to be brighter than LCDs with the same luminance [1,2].
However, there are several obstacles that hinder AMOLED displays from penetration into consumer electronic markets, such as the spatial and temporal variations of the TFT characteristics in LTPS and a-Si backplanes and the nonuniform electrical characteristics of OLEDs. In addition, there are issues related to the mass-production of AMOLEDs.
Voltage-mode driving methods offer the advantage of a fast driving speed for a wide data range. Among various voltage-mode driving methods, pixel circuits that compensates for variations in the threshold voltage were reported initially in [3]. This ...
