An Area and Power E fficient Source Driver IC With Multi-Line Sensing Real-Time Pixel Compensation for OLED Displays

Abstract

This article proposes a source driver integrated circuit (SD-IC) with a pixel compensator designed to mini- mize both silicon area and power consumption for organic light-emitting diode (OLED) displays. The proposed SD-IC is capable of driving ultrahigh-definition (UHD) active-matrix OLED (AMOLED) panels with a one-horizontal-time (1-H time) of 7.2µs while supporting a variable refresh rate (VRR). During VRR activation, the compensator senses the characteristics of the driving thin-film transistor (DTFT) and compensates for errors with real-time RGB data. By utilizing external compensation, each pixel adopts a 4T1C structure, which leads to a higher aperture ratio, enhanced luminance efficiency, and improved cost- effectiveness. The compensator integrates a noise reduction dual current conveyor (NDCC) and a dual slope error detector (DSED) to detect active pixel errors while minimizing the impact of panel noise. Additionally, a compensation channel multiplexer (CCM) enables to use a single compensator for sensing and adjust- ing multiple pixels. The proposed SD-IC was fabricated using a 250-nm CMOS process. After compensation, the maximum current error between two CMOS-modeled thin-film transistors (TFTs) with a 100-mV body-to-source voltage ( VBS) di fference was measured as 5.17 LSB, where 1 LSB corresponds to 0.59 nA. Compared to state-of-the-art compensators, the proposed pixel compensator achieves the smallest silicon area of 4442.8µm2 and the lowest power consumption of 13 .3