公开(公告)号：US09900938B2

公开(公告)日：2018-02-20

申请号：US15388243

申请日：2016-12-22

Applicant: FAIRCHILD KOREA SEMICONDUCTOR LTD.

Inventor： Jintae Kim ,  Hyunchul Eum ,  Inki Park ,  Eungwoo Lee

IPC: H05B33/08 ,  H02J3/01 ,  H02J3/18

CPC classification number: H05B33/0812 ,  H02J3/01 ,  H02J3/18 ,  H02M1/12 ,  Y02B20/345

Abstract: A light emitting diode (LED) lighting circuit includes a ripple reducer. The ripple reducer includes a ripple detector, an adaptive offset generator, and a linear regulator. The ripple detector generates a ripple voltage that is indicative of a ripple current. The adaptive offset generator generates an adaptive offset voltage from the ripple voltage and from a voltage of a transistor. The linear regulator drives the transistor to regulate an LED current in accordance with a reference control voltage that is generated from the ripple voltage and the adaptive offset voltage.

公开(公告)号：US10432187B2

公开(公告)日：2019-10-01

申请号：US15718338

申请日：2017-09-28

Applicant: FAIRCHILD KOREA SEMICONDUCTOR LTD.

Inventor： Taesung Kim ,  Seunguk Yang ,  Inki Park

IPC: H03B1/00 ,  H03K3/00 ,  H03K17/16 ,  H02M3/335 ,  H03K5/1532 ,  H03K17/60 ,  H03K17/082 ,  H03K17/687 ,  H02M1/00

Abstract: A power supply device includes a power switch that is switched according to a gate voltage. A sense resistor receives a switch current that flows through the power switch to develop a sense voltage. A peak of a primary-side current is detected from the sense voltage. The gate driver has a pair of switches for generating the gate voltage in accordance with a control signal. When a low-side switch of the gate driver is turned on according to the control signal, the gate voltage of the power switch decreases as a sink current flows from the gate of the power switch via the transistor.

公开(公告)号：US09986607B2

公开(公告)日：2018-05-29

申请号：US15610706

申请日：2017-06-01

Applicant: FAIRCHILD KOREA SEMICONDUCTOR LTD.

Inventor： Inki Park ,  Taesung Kim ,  Seunguk Yang

IPC: H05B37/02 ,  H05B33/08

CPC classification number: H05B33/0815 ,  H05B33/0842 ,  H05B33/089

Abstract: An LED control circuit controls a switching operation of a switch by hysteretic control. The LED control circuit includes a controller integrated circuit (IC) that senses a current sense voltage from a current sense resistor that is on a low-side of the switch. The LED control circuit senses the current sense voltage during on-time of the switch to determine when to turn off the switch. During off-time of the switch, the controller IC determines when to turn on the switch by comparing a sawtooth voltage to a turn-on threshold that is generated from the on-time of the switch.