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

[[abstract]]發光二極體具有許多的優點，重量輕薄、低功率消耗、體積小及使用時間壽命長久，而且沒有傳統的冷陰極射線管具有汞汙染的問題。因此發光二極體被運用在許多的科技商品中，本文研究之目的是在背光源使用，要設計一個快速的驅動發光二極體發亮與熄滅，且具有高均勻的亮度，以符合人眼觀賞最佳的視覺。 本論文中提出一個具有快速切換電流及三角積分調變發光二極體調光控制驅動電路，此驅動電路主要是由三角積分調變電路、低擺幅差動電路及快速切換電流構成驅動發光二極體電路。藉由三角積分調變電路的控制完成具有良好的光線的均勻性，而低擺差動電路和快速切換電流電路這兩個電路的組成，目的可以加速發光二極體驅動的時間，所以此驅動電路可以完成具有快速驅動發光二極體與高均勻度的特性。本論文的驅動電路設計是使用TSMC 0.25um 2.5V/5V/60V 1P5M BCD製程技術進行模擬與晶片的製作。[[abstract]]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.[[note]]碩