This paper presents a novel high precision and wide range adjustable LED constant-current drive controller design.Compared with the traditional technique,the conventional mirror resistance is substituted by a MOSFET w...This paper presents a novel high precision and wide range adjustable LED constant-current drive controller design.Compared with the traditional technique,the conventional mirror resistance is substituted by a MOSFET with fixed drain voltage,and a negative feedback amplifier is used to keep all mirror device voltages equal,so that the output current is precise and not affected by the load supply voltage.In addition,the electric property of the mirror MOSFET is optimized by a current subsection mirror（CSM） mechanism,thus ensuring a wide range of output current with high accuracy.A three-channel LED driver chip based on this project is designed and fabricated in the TSMC 0.6μm BCD process with a die area of 1.1×0.7 mm^2.Experimental results show that the proposed LED drive controller works well, and,as expected,the output current can be maintained from 5 to 60 mA.A relative current accuracy error of less than 1%and a maximal relative current matching error of 1.5%are successfully achieved.展开更多
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
基金supported by the National Ministry Pre-Research Foundation of China(No.9140A08010208DZ0123)the Applied Materials Innovation Foundation of Xi'an,China(No.XA-AM-200817)
文摘This paper presents a novel high precision and wide range adjustable LED constant-current drive controller design.Compared with the traditional technique,the conventional mirror resistance is substituted by a MOSFET with fixed drain voltage,and a negative feedback amplifier is used to keep all mirror device voltages equal,so that the output current is precise and not affected by the load supply voltage.In addition,the electric property of the mirror MOSFET is optimized by a current subsection mirror（CSM） mechanism,thus ensuring a wide range of output current with high accuracy.A three-channel LED driver chip based on this project is designed and fabricated in the TSMC 0.6μm BCD process with a die area of 1.1×0.7 mm^2.Experimental results show that the proposed LED drive controller works well, and,as expected,the output current can be maintained from 5 to 60 mA.A relative current accuracy error of less than 1%and a maximal relative current matching error of 1.5%are successfully achieved.
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.
