具有內置驅動電晶體之升壓切換式白光發光二極體驅動晶片設計

Design of the Boost Mode White LED Driver with Embedded MOSFET

黃振昌(Chen-Chang Huang)

指導教授 ： 宋國明

國立臺北科技大學/電資學院/電機工程系研究所/碩士(2009年)

摘要

本篇論文提出具有內置高壓切換電晶體的切換式白光發光二極體驅動晶片設計。電路設計架構上，是利用峰值電流控制的非連續導通電感電流來達成不需鋸齒波產生器和誤差放大器的精簡架構，並將高壓驅動電晶體整合於晶片中。本架構不同於傳統脈波寬度調變(PWM)電路，在一般的脈波寬度調變架構下，需要一個鋸齒波訊號和一個誤差放大器來與輸出訊號做誤差比較，以控制切換電晶體的動作。而本論文則利用固定頻率的振盪器加上高速比較器來偵測儲能電感的峰值電流，進而控制電晶體開關切換以達成電感之非連續導通電流工作模式。

本論文的晶片實現採用VIS 0.35μm HV，2P4M 互補金氧半混合信號製程，晶片Layout面積為0.65×0.60 mm2。輸入電壓範圍3.3~4.2V、輸出可驅動5顆串聯的白光發光二極體，系統轉換效率最高可達83.2%。

關鍵字

峰值電流控制 ； 非連續導通電流模式 ； 升壓轉換器

並列摘要

The thesis proposes a boost mode white LED driver with embedded switching MOSFET. The proposed structure is different from traditional PWM techniques. By using the peak current control and cooperate with discontinuous conduction method of the inductor switching current, the saw-tooth wave generator and error amplifier in a traditional PWM circuit can be eliminated. The proposed structure use a fixed frequency oscillator and a high speed comparator to detect the peak current of inductor then control the switching of MOSFET, by the above steps, the discontinuous conduction current in the inductor can be maintained and system able to generate 18V DC from 3.3V input to supply 5 white light LEDs in serial for small size LCD panel backlight module.

This design is implemented with VIS 0.35μm HV 2P4M mixed-mode CMOS process; chip layout area is 0.65×0.60mm2. The chip delivers regulated constant output power from a supply voltage range 3.3~4.2V and the power efficiency can up to 83.2% in maximum, while provided driving current of 5 white light LEDs in serial.

並列關鍵字

Peak Current Control ； Discontinuous Conduction Current Mode ； Boost

參考文獻

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