Patent · US Active

Adaptive algorithm for camera flash LED power control vs. battery impedance, state of discharge (SOD), aging, temperature effects

US7990074B2 · kind B2 · utility

5Cited by

4References

15Claims

0Family size

Assignee

TEXAS INSTRUMENTS DEUTSCHLAND GMBH · DE

Inventors

Harald Sandner · Marzling, DE
Christophe Vaucourt · Munich, DE
Hans Schmeller · Nieheim, DE
Martin Rommel · Freising, DE
Helmut Kiml · Ramstein-Miesenbach, DE

Key dates

Filing date	Oct 29, 2008
Grant date	Aug 2, 2011
Priority date	—
Expiry date	Dec 17, 2029

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY02B20/30
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

A method for driving a light-emitting semiconductor is provided. A supply voltage is converted into a secondary output voltage for supplying the light-emitting semiconductor with an output voltage. A level for the supply voltage at the beginning of a high current phase of the light-emitting semiconductor is sensed. A threshold voltage level for the supply voltage level is determined based on the sensed level. The high current phase with the light-emitting semiconductor is stated. The sensed level is continuously compared with the threshold voltage level, and an output current through the light-emitting semiconductor is controlled such that the sensed level does not drop below the threshold voltage level.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.