High-efficiency, high-dimming ratio LED driver

Author

Surkanti, Punith R. ; Furth, Paul M.

Author_Institution

Klipsch Sch. of Electr. & Comput. Eng., New Mexico State Univ., Las Cruces, NM, USA

fYear

2013

fDate

4-7 Aug. 2013

Firstpage

360

Lastpage

363

Abstract

A high-efficiency, high-dimming ratio LED driver, capable of driving two standard white LEDs in series, is presented in this paper. A synchronous boost converter with on-chip switches and PWM controller is used as the LED driver. The LED current is sensed using voltage-mode feedback to maintain a constant load current. The output sense resistor in a conventional LED driver is replaced by the disconnect switch with an equivalent on-resistance to increase efficiency. Lossless current-mode feedback, in which the inductor current is sensed via the on-resistance of the boost series switch, is used to improve stability. Dimming control logic is implemented with a 10-bit counter and a 10-to-1 MUX, generating 10 dimming ratios ranging from 2:1 at a frequency of 625 kHz to 1024:1 at 610 Hz. The simulated efficiency of the LED driver alone is 86.1% and that of the LED driver with dimming control is 85.4%.

Keywords

PWM power convertors; driver circuits; light emitting diodes; switches; LED current; PWM controller; dimming control logic; disconnect switch; efficiency 85.4 percent; efficiency 86.1 percent; equivalent on-resistance; frequency 610 Hz; frequency 625 kHz; high-efficiency high-dimming ratio LED driver; inductor current; lossless current-mode feedback; on-chip switches; synchronous boost converter; voltage-mode feedback; white LED; word length 10 bit;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems (MWSCAS), 2013 IEEE 56th International Midwest Symposium on

Conference_Location

Columbus, OH

ISSN

1548-3746

Type

conf

DOI

10.1109/MWSCAS.2013.6674660

Filename

6674660