Title :
A fast-switching current-pulse driver for LED backlight
Author :
Kim, Jang-Su ; Lee, Yong-Kyu ; Lee, Jee-Sue ; Shin, Young-Kyu ; Tark, Jung-Hyun ; Ryu, Keun-Chul ; Yang, Byung-Do
Author_Institution :
VLSI Circuit & Syst. Lab., Chungbuk Nat. Univ., Cheongju, South Korea
Abstract :
In this paper, a fast-switching current-pulse driver for light emitting diodes (LED) backlight is proposed. It uses a regulated drain current mirror (RD-CM) and a high-voltage NMOS transistor (HV-NMOS). It achieves the fast-response current-pulse switching by using a dynamic gain-boosting amplifier (DGB-AMP). The DGB-AMP does not discharge the large HV-NMOS gate capacitance of the RD-CM when the output current switch turns off. Therefore, it does not need to charge the HV-NMOS gate capacitance when the switch turns on. The proposed current-pulse driver achieves the fast current switching by removing the repetitive gate discharging and charging. Simulation results were verified with measurements performed on a fabricated chip using a 5 V/40 V 0.5 mum BCD process. It reduces the switching delay to 360 ns from 700 ns of the conventional current-pulse driver.
Keywords :
MOSFET; driver circuits; light emitting diodes; mirrors; power amplifiers; DGB-AMP; LED backlight; dynamic gain-boosting amplifier; fast-response current-pulse switching; fast-switching current-pulse driver; gate capacitance; high-voltage NMOS transistor; light emitting diodes; regulated drain current mirror; size 0.5 mum; voltage 40 V; voltage 5 V; Brightness; Capacitance; Driver circuits; Light emitting diodes; Lighting control; Liquid crystal displays; MOSFETs; Mirrors; Pulse width modulation; Switches;
Conference_Titel :
Circuits and Systems, 2009. ISCAS 2009. IEEE International Symposium on
Conference_Location :
Taipei
Print_ISBN :
978-1-4244-3827-3
Electronic_ISBN :
978-1-4244-3828-0
DOI :
10.1109/ISCAS.2009.5118120
