| Summary: | 碩士 === 國立臺北科技大學 === 自動化科技研究所 === 98 === This thesis focuses on the design of the white LED backlight driver with 3-bit dimming controller. By using the voltage-mode pulse width modulation, the power MOS duty cycle can be modified and the switching DC-DC boost converter can be implemented. Furthermore, a 3-bit digital-to-analog converter, a ramp and oscillator generator are needed to generate eight pulse-width signals through a voltage comparator. Thus, a 3-bit dimming controller can be implemented with the duty cycle of current for white LEDs.
In this thesis, the proposed chip is designed and implemented with TSMC 0.35 μm 2P4M CMOS process. The simulation results of the switching DC-DC boost converter show that the input voltage, chip area, output voltage, and output current are 3.7 V, 1.45 ´ 1.28 mm2, 20 V, and 20 mA, respectively. This output voltage can drive five white LEDs with driving voltage of 3.5 V and driving current of 20 mA; the duty cycle and the brightness of white LEDs can be adjusted through the proposed dimming controller.
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