Abstract：Among the current sharing schemes of multi-channel LEDs, the scheme based on charge and discharge balance of capacitor is simple, accurate, low cost and high reliability. In this paper, a novel multi-channel LED driver topology is proposed, combined the switch-controlled capacitor (SCC) with the charge and discharge balance of capacitors. The operating period of SCC, the working mode of the module and the simplified equivalent circuit are analyzed in detail. The control curves of LED drive current versus the equivalent capacitance are obtained. A four-channel LED driver prototype was built up with good current sharing performance and expansibility. The controllable range of drive current is from 180mA to 350mA per channel. The prototype can achieve accurate current sharing of two-channel LED within a module, accurate current sharing of four-channel LED within different modules, and the independent dimming of different modules.
曾君, 孙伟华, 刘俊峰. 基于可控开关电容充放电平衡的多路LED驱动器[J]. 电工技术学报, 2017, 32(18): 267-275.
Zeng Jun, Sun Weihua, Liu Junfeng. Multi-Channel LED Driver Based on Charging and Discharging Balance of Switch-Controlled Capacitor. Transactions of China Electrotechnical Society, 2017, 32(18): 267-275.
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2017, Vol. 32 
