驅動電路積體化設計應用於發光二極體自動功率控制之研究

Study on Integrated Driver Circuit Design for Light Emitting Diode with Automatic Power Control

陳建彬(Robin)

指導教授 ： 孫台平

國立暨南國際大學/科技學院/電機工程學系/碩士(2009年)

摘要

本論文提出一個不需光二極體迴授控制的積體化發光二極體自動功率控制驅動電路設計，以降低溫度對光功率變化量的影響。驅動電路架構包含：一個儀表放大器，來偵測發光二極體的順向電壓。一個乘法器是用於量測發光二極體的消耗功率。一個反相放大器當溫度補償電路。一個電壓電流轉換器是用於轉換電壓成電流形式以及電流鏡提供驅動電流給發光二極體。為了模擬驗證此驅動電路的功能，我們由LED的電及光特性的量測建立了發光二極體的SPICE模型。量測結果顯示電路用定電功率來驅動發光二極體，當溫度由10°C升至70°C時，減少光功率變化量從使用定電流的16.1% 至11.3%。這個驅動電路是使用台灣積體電路製造股份有限公司所提供的0.35μm 2P4M 3.3V/5V混合訊號互補式金氧半製程來製造。本晶片在5 V的供應電壓下，可提供最大電流輸出為10 mA.

關鍵字

LED驅動電路 ； 自動功率控制 ； 乘法器 ； LED SPICE模型

並列摘要

This thesis presents an integrated LED driver circuit with an automatic power control to reduce optical power variation due to temperature without using photodiode. The driver circuit consists of an instrumentation amplifier for detecting the forward voltage of the LED; a multiplier for measuring electrical power of the LED; an inverting amplifier as temperature compensation circuit; a voltage-to-current converter for converting a voltage signal into a current signal; and current mirrors for providing drive current to the LED. In order to simulate the function of the driver circuit, a LED SPICE model based on electrical and optical measurement of the LED was built. The measurement results show that the driver circuit drives the LED with constant electrical power and reduce light power variation from 16.1%, if LED is driven by a fixed constant current, to 11.3% over the temperature range of 10°C to 70°C. The driver circuit has been designed and fabricated with TSMC 0.35 μm 2P4M 3.3V/5V mixed signal CMOS process. The chip operates at 5 V power supply with 10 mA maximum output current.

並列關鍵字

LED driver ； automatic power control ； multiplier ； LED SPICE model

參考文獻

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