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. 24, 2015

Filed:

May. 03, 2011
Applicant:

Yongman Lee, Pleasanton, CA (US);

Inventor:

Yongman Lee, Pleasanton, CA (US);

Assignee:

APPLE INC., Cupertino, CA (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G09G 3/36 (2006.01);
U.S. Cl.
CPC ...
G09G 3/3677 (2013.01); G09G 3/3696 (2013.01); G09G 2320/0223 (2013.01); G09G 2320/0252 (2013.01);
Abstract

Techniques for controlling the slew rate of a signal independently of RC time constants are disclosed. In one embodiment, a gate driver circuit for an LCD panel may include a rail-to-rail operational amplifier having an output stage configured to produce a gate activation signal for switching pixels of the LCD panel. A slew rate control circuit may be provided for adjusting the slew rate of the gate activation signal by varying a bias current of the output stage relative to a compensation capacitance and a gain of the operational amplifier. For instance, the slew rate may be increased by increasing the bias current, and decreased by decreasing the bias current without the need to adjust RC variables.


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