A Current-Mode Display Driver IC Using Sample-and-Hold Scheme for QVGA Full-Color AMOLED Displays

A display driver IC based on a current-sink driving scheme has been developed for QVGA (240times320), low-temperature poly-silicon (LTPS) active matrix organic light-emitting diodes (AMOLEDs) displays. The current-mode driver IC consists of a source driver block and a controller block. It uses a sample-and-hold scheme in the source driver block. The source driver block has 720 channel outputs, an 8-bit segmented DAC, a pre-charge generation block, and a 64-level gray scale (64 selections out of 256 gray levels for Gamma correction) per channel. The source driver output current ranges from 10 nA to 10 mum. The controller block generates control signals for the source driver and LTPS drivers (emission and scan driver), which are integrated on the panel glass. The current-mode driver IC was fabricated in a 0.18-mum CMOS technology (two poly and four metals) with 5.3-V high-voltage transistor devices

[1]  Tatsuya Shimoda,et al.  Classification of Driving Methods for TFT-OLEDs and Novel Proposal Using Time Ratio Grayscale and Current Uniformization , 2005, IEICE Trans. Electron..

[2]  Masao Nakaya,et al.  An 80-MHz 8-bit CMOS D/A converter , 1986 .

[3]  Haiqing Lin,et al.  An 852/spl times/600 pixel OLED-on-silicon color microdisplay chip using CMOS sub-threshold-voltage-scaling current driver , 2002 .

[4]  S. Pearson,et al.  The impact of the transient response of organic light emitting diodes on the design of active matrix OLED displays , 1998, International Electron Devices Meeting 1998. Technical Digest (Cat. No.98CH36217).

[5]  W. Guggenbuhl,et al.  Switched-current memory circuits for high-precision applications , 1994 .

[6]  Ian O'Connor,et al.  Automated synthesis of current-memory cells , 2000, IEEE Trans. Comput. Aided Des. Integr. Circuits Syst..

[7]  Tae Jin Kim,et al.  A Current Driver IC using a S/H for QVGA FullColor Active-Matrix Organic LED Mobile Displays , 2006, 2006 IEEE International Solid State Circuits Conference - Digest of Technical Papers.

[8]  M.N.S. Swamy,et al.  Design of a transistor-mismatch-insensitive switched-current memory cell , 1999, ISCAS'99. Proceedings of the 1999 IEEE International Symposium on Circuits and Systems VLSI (Cat. No.99CH36349).

[9]  Hai-Jung In,et al.  P‐8: A Novel Feedback‐Type AMOLEDs Driving Method for Large‐Size Panel Applications , 2005 .

[10]  Stephen R. Forrest,et al.  The dawn of organic electronics , 2000 .