公开(公告)号：US09635746B2

公开(公告)日：2017-04-25

申请号：US13693516

申请日：2012-12-04

Applicant: Magnachip Semiconductor, Ltd.

Inventor： Jun-sik Min ,  Tae-kyoung Kang ,  Beom-seon Ryu

IPC: H05B33/08 ,  H05B37/03

CPC classification number: H05B37/03 ,  H05B33/0827 ,  H05B33/0887

Abstract: A detecting circuit and method thereof are configured to detect whether an LED array is open is described. The detecting circuit includes a resistance unit, a first switching unit, and an output unit. The resistance unit is operatively connected in series to the LED array. The switching unit is configured to be turned on when a voltage of the resistance unit is greater than or equal to a predetermined voltage level. The output unit is configured to produce an output indicative of whether the LED array is open, based whether the first switching unit is turned on.

公开(公告)号：US09603220B2

公开(公告)日：2017-03-21

申请号：US13693223

申请日：2012-12-04

Applicant: MAGNACHIP SEMICONDUCTOR, LTD.

Inventor： Tae-kyoung Kang

IPC: H05B37/02 ,  H05B33/08

CPC classification number: H05B37/02 ,  H05B33/0815 ,  H05B33/0848 ,  Y02B20/346

Abstract: A light-emitting diode (LED) driver apparatus is provided. The LED driver apparatus includes a pulse width modulation (PWM) signal generating unit, a DC-DC converter, and a comparison voltage generating unit. The PWM signal generating unit generates a PWM signal according to a comparison voltage. The DC-DC converter supplies a driving voltage of an LED array by using the PWM signal. The comparison voltage generating unit measures a feedback voltage of the LED array and supplies a difference between the measured feedback voltage and a target voltage as a comparison voltage to the PWM signal generating unit. The comparison voltage generating unit supplies a second reference voltage as a comparison voltage to the PWM signal generating unit from a time when the driving voltage is higher than or equal to a first reference voltage to a time when the driving voltage reaches the target voltage.

公开(公告)号：US09888552B2

公开(公告)日：2018-02-06

申请号：US13693241

申请日：2012-12-04

Applicant: Magnachip Semiconductor, Ltd.

Inventor： Tae-kyoung Kang ,  Gyu-ho Lim ,  Beom-seon Ryu ,  Jun-sik Min

IPC: H05B37/03 ,  H05B33/08

CPC classification number: H05B37/036 ,  H05B33/089

Abstract: A detection circuit configured to detect a short in a plurality of LED arrays is provided. The detection circuit includes a voltage measuring unit, a short detecting unit, and a detection control unit. The voltage measuring unit is configured to measure respective feedback voltages of the plurality of LED arrays and output a lowest measured feedback voltage as a first feedback voltage. The short detecting unit is configured to detect the short in the LED arrays using the measured feedback voltages. The detection control unit is configured to control the short detecting unit to stop short detection operation, when the first feedback voltage exceeds a first preset reference voltage.