AM PWM Driving Circuit for Mini-LED Backlight in Liquid Crystal Displays
Autor: | Yuan-Hao Ho, Wei-Sheng Liao, Chih-I Liu, Jia-Tian Peng, Ming-Yang Deng, S.F. Chen, Chih-Lung Lin, Chieh-An Lin, Chia-Ling Tsai, Chia-En Wu |
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Rok vydání: | 2021 |
Předmět: |
Backlight
01 natural sciences law.invention pulse-width modulation law 0103 physical sciences Electrical and Electronic Engineering 010302 applied physics Physics Liquid-crystal display LCD backlight business.industry Transistor power consumption high dynamic range Active-matrix display mini-LED TK1-9971 Electronic Optical and Magnetic Materials Power (physics) Threshold voltage Thin-film transistor Pulse-amplitude modulation Optoelectronics Electrical engineering. Electronics. Nuclear engineering business Pulse-width modulation Biotechnology |
Zdroj: | IEEE Journal of the Electron Devices Society, Vol 9, Pp 365-372 (2021) |
ISSN: | 2168-6734 |
DOI: | 10.1109/jeds.2021.3065905 |
Popis: | This work proposes a mini-LED driving circuit that adopts the pulse-width modulation (PWM) driving method for use in a liquid-crystal display (LCD) backlight. The proposed circuit can compensate for the threshold voltage ( $\text{V}_{\mathrm{ TH}}$ ) variation in a low-temperature poly-crystalline silicon thin-film transistor (LTPS TFT) and a VSS current-resistance (I-R) rise, to generate a stable driving current to power the mini-LED. Since the proposed circuit uses the PWM method, the mini-LED can be operated at the best luminance-efficacy point, minimizing the power consumption of the circuit. The electrical characteristic of fabricated LTPS TFTs are measured to establish a simulation model to demonstrate the feasibility of the proposed circuit. Simulation results demonstrate that the relative mini-LED current error rates are below 9% when the $\text{V}_{\mathrm{ TH}}$ varies ± 0.3 V and VSS rises by 1 V. With respect to precise control of the gray level, the time shifts of current pulses are within 11.48 us over the whole grayscale. The improvement in the power consumption of the proposed circuit is more than 21% than that of a circuit that is driven by pulse amplitude modulation. |
Databáze: | OpenAIRE |
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