Application enhancement for driving large strings of LEDs

Author

Pristavu, G. ; Vasilica, Anca ; Anghel, Vlad ; Brezeanu, G.

Author_Institution

Dept. of Electr. Devices & Circuits, Univ. Politeh. of Bucharest, Bucharest, Romania

fYear

2014

fDate

13-15 Oct. 2014

Firstpage

207

Lastpage

210

Abstract

A technique for increasing the number of series connected LEDs driven by a current-mode floating buck converter is analyzed, simulated and implemented. The converter uses an external power switch, driven by a previously introduced low-cost variable frequency controller. The increase in input voltage and number of driven LEDs is achieved by the addition of a level shifter at the controller´s output which enhances its capability to drive a power MOSFET switch. Measurements performed on the improved converter biasing a maximum of 16 LEDs at up to 75V emphasize a peak efficiency of 94.6%. An efficiency over 87% can be obtained in all cases.

Keywords

driver circuits; frequency control; light emitting diodes; power MESFET; power convertors; current-mode floating buck converter; external power switch; level shifter; low-cost variable frequency controller; power MOSFET switch; series connected LED; CMOS integrated circuits; CMOS technology; Light emitting diodes; Switches; Switching circuits; Voltage control; LED driver; current-mode floating buck converter; external switch; level shifter;

fLanguage

English

Publisher

ieee

Conference_Titel

Semiconductor Conference (CAS), 2014 International

Conference_Location

Sinaia

ISSN

1545-827X

Print_ISBN

978-1-4799-3916-9

Type

conf

DOI

10.1109/SMICND.2014.6966437

Filename

6966437