公开(公告)号：US10405381B2

公开(公告)日：2019-09-03

申请号：US15601034

申请日：2017-05-22

申请人： FAIRCHILD KOREA SEMICONDUCTOR LTD.

发明人： Minwoo Lee ,  Moonsik Song ,  Seunguk Yang

IPC分类号： H05B33/08 ,  H05B37/02

摘要： A light emitting diode (LED) control circuit includes an inductor current sense circuit with a high-side diode string, a low-side diode string, and a sense resistor in series with and between the high-side and low side diode strings. The LED control circuit receives an input voltage on an end that connects to the high-side diode string. An end of the low-side diode string is connected to a switch through an inductor. A sense voltage developed on the sense resistor by an inductor current is sensed by a controller integrated circuit (IC). A pin of the controller IC that receives the sense voltage can have a breakdown voltage specification that is lower than the input voltage.

公开(公告)号：US10104728B2

公开(公告)日：2018-10-16

申请号：US15380254

申请日：2016-12-15

申请人： FAIRCHILD KOREA SEMICONDUCTOR LTD.

发明人： Minwoo Lee ,  Moonsik Song ,  Seunguk Yang

IPC分类号： H05B37/02 ,  H05B33/08

摘要： A light emitting diode (LED) driving circuit disclosed herein controls a switching operation of a power switch connected to an LED string and includes a reference voltage generator configured to generate a frequency modulation reference voltage according to a dimming signal that controls brightness of the LED string, and a switching controller configured to control a switching frequency of the power switch to be constant when a level of the dimming signal is higher than that of the frequency modulation reference voltage, and control the switching frequency of the power switch based on the dimming signal when a level of the dimming signal is lower than that of the frequency modulation reference voltage.

公开(公告)号：US09900948B2

公开(公告)日：2018-02-20

申请号：US15380248

申请日：2016-12-15

申请人： FAIRCHILD KOREA SEMICONDUCTOR LTD.

发明人： Minwoo Lee ,  Moonsik Song

IPC分类号： H05B37/02 ,  H05B33/08

CPC分类号： H05B33/0845 ,  H05B33/0815 ,  H05B33/0887

摘要： A reference voltage generator disclosed herein includes an amplifier including two input terminals connected to a dimming signal and a first node, respectively, and an output terminal, a first transistor including a gate connected to the output terminal of the amplifier and one electrode connected to the first node, second and third transistors configured to form a current mirror, and two resistors connected between one electrode of the second transistor and one electrode of the first transistor.