公开(公告)号：US09072147B2

公开(公告)日：2015-06-30

申请号：US14264518

申请日：2014-04-29

Applicant: Linear Technology Corporation

Inventor： Keith D. Szolusha ,  Joshua W. Caldwell ,  Bryan Legates

IPC: H05B33/08 ,  H05B41/28

CPC classification number: H05B33/0851 ,  H05B33/0809 ,  H05B33/0815 ,  H05B33/0818 ,  H05B41/28 ,  Y02B20/346 ,  Y02B20/347

Abstract: In a method for controlling a current regulator for dimming an LED load, a dimming signal has a duty cycle that controls the LED ON-time and LED OFF time at a fixed frequency. The regulator is controlled by the dimming signal to only supply current to the LED load during the LED ON-time. The regulator includes an inductor. The inductor current at the end of an ON-time is detected and its value is stored. During the OFF-time, the inductor is pre-charged to the current level matching the stored value, while the regulator's feedback loop is frozen during the OFF-time to not change its feedback control signal. Upon the next ON-time, the regulator begins supplying current to the LED load with the pre-charged inductor current, so there is no initial decrease in the delivered LED current. Therefore, the current pulse magnitudes are constant even with very low duty cycles.

Abstract translation: 在用于控制用于调光LED负载的电流调节器的方法中，调光信号具有以固定频率控制LED接通时间和LED关闭时间的占空比。 调光器由调光信号控制，以便在LED接通时间期间仅向LED负载提供电流。 调节器包括电感器。 检测接通时间结束时的电感电流，并存储其值。 在关断期间，电感器预充电到与存储值匹配的电流电平，而稳压器的反馈环路在关断时间冻结，不改变其反馈控制信号。 在下一个导通时间后，调节器开始向预充电电感电流的LED负载供电，因此LED电流的传送没有初始减少。 因此，即使在非常低的占空比下，当前脉冲幅度也是恒定的。

公开(公告)号：US20150145439A1

公开(公告)日：2015-05-28

申请号：US14264518

申请日：2014-04-29

Applicant: Linear Technology Corporation

Inventor： Keith D. Szolusha ,  Joshua W. Caldwell ,  Bryan Legates

IPC: H05B33/08

CPC classification number: H05B33/0851 ,  H05B33/0809 ,  H05B33/0815 ,  H05B33/0818 ,  H05B41/28 ,  Y02B20/346 ,  Y02B20/347

Abstract: In a method for controlling a current regulator for dimming an LED load, a dimming signal has a duty cycle that controls the LED ON-time and LED OFF time at a fixed frequency. The regulator is controlled by the dimming signal to only supply current to the LED load during the LED ON-time. The regulator includes an inductor. The inductor current at the end of an ON-time is detected and its value is stored. During the OFF-time, the inductor is pre-charged to the current level matching the stored value, while the regulator's feedback loop is frozen during the OFF-time to not change its feedback control signal. Upon the next ON-time, the regulator begins supplying current to the LED load with the pre-charged inductor current, so there is no initial decrease in the delivered LED current. Therefore, the current pulse magnitudes are constant even with very low duty cycles.

Abstract translation: 在用于控制用于调光LED负载的电流调节器的方法中，调光信号具有以固定频率控制LED接通时间和LED熄灭时间的占空比。 调光器由调光信号控制，以便在LED接通时间期间仅向LED负载提供电流。 调节器包括电感器。 检测接通时间结束时的电感电流，并存储其值。 在关断期间，电感器预充电到与存储值匹配的电流电平，而稳压器的反馈环路在关断时间冻结，不改变其反馈控制信号。 在下一个导通时间后，调节器开始向预充电电感电流的LED负载供电，因此LED电流的传送没有初始减少。 因此，即使在非常低的占空比下，当前脉冲幅度也是恒定的。