Cart (Loading....) | Create Account
Close category search window
 

A High-Dimming-Ratio LED Driver for LCD Backlights

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

6 Author(s)
Yuan-Ta Hsieh ; Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan ; Bin-Da Liu ; Jian-Fu Wu ; Chiao-Li Fang
more authors

The grayscale resolution of liquid crystal displays (LCDs) can be improved by modulating the grayscale of the pixels in LCDs or by dimming the LCD backlight source. Changing the voltage or turned-on time of a pixel to achieve high-resolution grayscale requires either an accurate digital-to-analog converter or a very high frequency pulsewidth modulation (PWM) signal, which increases hardware cost and power consumption. The fast transient response of light-emitting diodes (LEDs) makes them useful as a backlight source for improving the grayscale resolution of an LCD without additional overhead. This paper presents an eight-channel LED backlight driver that can improve conventional dimming control circuits for LCDs. The proposed design was fabricated in a TSMC 0.25-μm 60-V bipolar-CMOS-DMOS process, and the chip area is 2.7 mm2. A dimming ratio of 50 000:1 is achieved with a 500-Hz PWM signal. The maximum power conversion efficiency, including power consumption of the LED current regulators, is 89.3%, when the load is a 12 × 8 LED array, the input voltage is 20 V, and the LED current is set to 25 mA.

Published in:

Power Electronics, IEEE Transactions on  (Volume:27 ,  Issue: 11 )

Date of Publication:

Nov. 2012

Need Help?


IEEE Advancing Technology for Humanity About IEEE Xplore | Contact | Help | Terms of Use | Nondiscrimination Policy | Site Map | Privacy & Opting Out of Cookies

A not-for-profit organization, IEEE is the world's largest professional association for the advancement of technology.
© Copyright 2014 IEEE - All rights reserved. Use of this web site signifies your agreement to the terms and conditions.