A 402-output TFT-LCD driver IC with power control based on the number of colors selected

Author

Itakura, Tetsuro ; Minamizaki, Hironori ; Saito, Tetsuya ; Kuroda, Tadashi

Author_Institution

Mobile Commun. Lab., Toshiba Corp., Kawasaki, Japan

Volume

38

Issue

3

fYear

2003

fDate

3/1/2003 12:00:00 AM

Firstpage

503

Lastpage

510

Abstract

A 402-output thin-film-transistor liquid crystal display (TFT-LCD) driver integrated circuit (IC) with power control based on the number of colors to be displayed is described. To achieve this type of power control, reference voltage buffers are turned on and off according to the selected number of colors. In this architecture, the reference voltage buffers must drive 1-402 capacitive loads, corresponding to a capacitance of 30-12000 pF. Phase compensation using a zero formed with capacitive loads is proposed for the reference voltage buffers. The introduced zero has a fixed zero frequency for 1-402 loads. An operational amplifier with slew-rate enhancement is also proposed for the buffers. An experimental 402-output TFT-LCD driver IC was fabricated using a 0.6-μm CMOS technology. The chip size was 2.35 mm × 18.1 mm. The quiescent current dissipation of the analog section including decoders was 529 μA for 262144 colors, 182 μA for 4096 colors, and 112 μA for 512 colors for a 5-V supply.

Keywords

CMOS analogue integrated circuits; buffer circuits; colour displays; driver circuits; liquid crystal displays; power control; reference circuits; thin film transistors; 0.6 micron; 112 muA; 18.1 mm; 182 muA; 2.35 mm; 30 to 12000 pF; 402-output TFT-LCD driver IC; 5 V; 529 muA; CMOS technology; capacitive load driving; chip size; color display; color selection; fixed zero frequency; introduced zero; operational amplifier; phase compensation; power control; quiescent current dissipation; reference voltage buffers; slew-rate enhancement; CMOS integrated circuits; CMOS technology; Capacitance; Decoding; Driver circuits; Frequency; Liquid crystal displays; Operational amplifiers; Power control; Voltage;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/JSSC.2002.808308

Filename

1183859