The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
May. 02, 2017

Filed:

Jan. 06, 2015
Applicant:

Magnachip Semiconductor, Ltd., Cheongju-si, KR;

Inventors:

Gyu Ho Lim, Cheongju-si, KR;

Jun Sik Min, Cheongju-si, KR;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05B 33/08 (2006.01); G05F 1/56 (2006.01);
U.S. Cl.
CPC ...
H05B 33/0812 (2013.01); G05F 1/561 (2013.01); Y02B 20/345 (2013.01);
Abstract

Disclosed is a circuit for compensating a bipolar junction transistor (BJT) base current that mirrors the BJT base current to induce a mirror current that is coupled to an emitter of the BJT to decrease an emitter current by a size of the mirror current. Also disclosed is a light-emitting diode (LED) driving apparatus including an LED array, a BJT series-coupled to the LED array, a measuring unit coupled to an emitter of the BJT to measure a current flowing into the LED array, a differential amplifier configured to differentially amplify a reference voltage and the measured current to supply a base current to a base of the BJT, and a BJT base current compensation circuit as disclosed to accurately control an LED current.


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