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:
Nov. 13, 2018

Filed:

Aug. 30, 2017
Applicant:

Apple Inc., Cupertino, CA (US);

Inventors:

Mohammad J. Navabi-Shirazi, San Jose, CA (US);

Jingdong Chen, San Jose, CA (US);

Asif Hussain, San Jose, CA (US);

Yanhui Xie, Santa Clara, CA (US);

Assignee:

Apple Inc., Cupertino, CA (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05B 37/02 (2006.01); H05B 33/08 (2006.01);
U.S. Cl.
CPC ...
H05B 33/0824 (2013.01); H05B 33/0845 (2013.01);
Abstract

Aspects of the subject technology relate to display circuitry such as backlight control circuitry for operating light-emitting diodes (LEDs). The backlight control circuitry may include a pulse-width-modulation (PWM) transistor and a current regulation transistor coupled in series with at least one LED. The current regulation transistor may have a gate terminal that receives a feedback-controlled gate voltage. The backlight control circuitry may include a gate clamp circuit coupled to the gate terminal of the current regulation transistor that clamps the gate voltage during a portion of a PWM on pulse.


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