Study of LED Dimming Controller with Fast Switching Current Driving and Delta-Sigma Modulation

• Main Authors: Kai-zen Chang, 詹鎧任
• Other Authors: Chih-Wen Lu
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/59000971983581115706

碩士 === 國立暨南國際大學 === 電機工程學系 === 99 === Light Emitting Diodes (LED) has many advantages, light weight, low power consumption, small volume, long life-time, and there is no conventional Cold Cathode Fluorescent Lamp (CCFL) with mercury pollution. Therefore LED was applied in many technological commodities. This study was to use for the backlight. In this thesis, to design a fast drive LED illuminated and off, and has a high uniform brightness to match the best visual eye view. In this thesis, we have proposed a LED dimming controller with fast-switching current driving and delta-sigma modulation. The proposed LED dimming controller is composed of a delta-sigma modulation, a low voltage swing differential output circuit, and a fast switching current LED driver. The proposed controller achieves good uniformity of brightness using dimming control with Delta-Sigma Modulation. In order to achieve high efficiency, a low voltage swing differential output circuit and a fast switching current LED driver are introduced to speed up the switching time. This driver circuit design was simulated and fabricated chip using a TSMC 0.25um 2.5V/5V/60V 1P5M BCD process.