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. 18, 2021

Filed:

Feb. 28, 2018
Applicant:

Semiconductor Energy Laboratory Co., Ltd., Atsugi, JP;

Inventor:

Roh Yamamoto, Toyama, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G09G 3/00 (2006.01); G01R 31/28 (2006.01); G01R 35/00 (2006.01); G09G 3/32 (2016.01); H01L 27/32 (2006.01); H01L 51/52 (2006.01);
U.S. Cl.
CPC ...
G09G 3/006 (2013.01); G01R 31/2884 (2013.01); G01R 35/00 (2013.01); G09G 3/32 (2013.01); G09G 2300/08 (2013.01); G09G 2310/0289 (2013.01); G09G 2310/0291 (2013.01); G09G 2310/0294 (2013.01); G09G 2320/0295 (2013.01); G09G 2330/12 (2013.01); H01L 27/3246 (2013.01); H01L 27/3262 (2013.01); H01L 27/3265 (2013.01); H01L 27/3276 (2013.01); H01L 51/5253 (2013.01); H01L 51/5259 (2013.01);
Abstract

A test circuit is incorporated in an IC without an increase in a chip area. The IC includes a plurality of pins, a plurality of current sensing circuits, and a current generation circuit. The plurality of current sensing circuits process currents flowing through the plurality of pins in parallel and generates digital data, for example. The current generation circuit includes a capacitor and generates a reference current corresponding to the amount of electric charge of the capacitor. The amount of electric charge can be controlled by a voltage input to the capacitor, and thus the range of output currents for current generation can be made wide. The reference current is used for testing the plurality of current sensing circuits. The IC is used for a source driver IC of a display panel, for example. In this case, currents flowing through pixels in the display panel can be sensed by the plurality of current sensing circuits.


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