This paper presents a high dimming ratio light emitting diode （LED） drive controller chip with digital mode dimming （DMD）. The chip is composed of a boost power converter and a dimming control block. A novel const...This paper presents a high dimming ratio light emitting diode （LED） drive controller chip with digital mode dimming （DMD）. The chip is composed of a boost power converter and a dimming control block. A novel constant on time （COT） control strategy is proposed for boost converter to achieve high dimming ratio. In addition, a fast enough load transient response of the converter power stage ensures its high dimming ratio. The COT control circuit operates mainly based on two current-capacitor timers and a finite state machine （FSM）. The LED drive controller chip is designed and fabricated in 1.5μm bipolar CMOS-DMOS （BCD） process with a die area of 1.31 x 1.43 mm^2. Experimental results show that the proposed LED drive system works well. And, as expected, the minimum LED dimming on time of 1.0μs and the corresponding dimming ratio of 1000 ： 1 at 1 kHz dimming frequency are successfully achieved.展开更多
建立了四轮驱动汽车加速过程的数学模型,以滑转率为调节对象,提出一种基于模糊P ID控制的驱动防滑控制A SR算法。设计了以发动机油门为控制对象的模糊-P ID控制器并讨论了控制器切换参数的选取,并针对均一低附着路面以及分离路面在S im ...建立了四轮驱动汽车加速过程的数学模型,以滑转率为调节对象,提出一种基于模糊P ID控制的驱动防滑控制A SR算法。设计了以发动机油门为控制对象的模糊-P ID控制器并讨论了控制器切换参数的选取,并针对均一低附着路面以及分离路面在S im u link仿真环境下进行了动态仿真。对比仿真结果,表明模糊P ID控制性能优于单一的模糊控制。展开更多
基金supported by the National Natural Science Foundation of China (No. 90707002).
文摘This paper presents a high dimming ratio light emitting diode （LED） drive controller chip with digital mode dimming （DMD）. The chip is composed of a boost power converter and a dimming control block. A novel constant on time （COT） control strategy is proposed for boost converter to achieve high dimming ratio. In addition, a fast enough load transient response of the converter power stage ensures its high dimming ratio. The COT control circuit operates mainly based on two current-capacitor timers and a finite state machine （FSM）. The LED drive controller chip is designed and fabricated in 1.5μm bipolar CMOS-DMOS （BCD） process with a die area of 1.31 x 1.43 mm^2. Experimental results show that the proposed LED drive system works well. And, as expected, the minimum LED dimming on time of 1.0μs and the corresponding dimming ratio of 1000 ： 1 at 1 kHz dimming frequency are successfully achieved.
文摘建立了四轮驱动汽车加速过程的数学模型,以滑转率为调节对象,提出一种基于模糊P ID控制的驱动防滑控制A SR算法。设计了以发动机油门为控制对象的模糊-P ID控制器并讨论了控制器切换参数的选取,并针对均一低附着路面以及分离路面在S im u link仿真环境下进行了动态仿真。对比仿真结果,表明模糊P ID控制性能优于单一的模糊控制。
