本論文主旨為研製液晶顯示器RGB LED 背光模組
之高效能驅動電源,DC/DC 轉換器採用半橋串聯諧振電
路架構,供應RGB LED 背光源所需之驅動電壓,其具
有零電壓切換特性可提高轉換效率。本文提出相移式
PWM 均流控制策略,可藉由改變PWM 責任週期而達
到白平衡。因為LED 的特性會隨著溫度改變,所以增加
一偵測LED 電壓的控制電路,以避免額外的損失。最後
設計一個實例電路,並將所量測的實驗數據結果驗證電
源架構及控制方法的可行性。
This thesis presents a high-performance power supply
for driving an RGB LED backlight module of the liquid
crystal display (LCD). A half-bridge series resonant
converter (SRC) with zero-voltage switching is adopted as
the DC/DC converter to drive the RGB LED arrays. A
phase-shifted pulse width modulation (PSPWM) dimming
control is presented to track the white-color point. Since
the LED voltages vary with the temperature, voltage
sensors detecting the voltage drops of the linear regulators
are used. Then the feedback signals are sent to adjust the
output voltage levels of the SRCs to cut down the power
losses on the linear regulators. A prototype driver system is
implemented. The feasibilities of the circuit topology and
the control strategy are verified by the experimental results.