A Digital boost converter to drive white LEDs
Journal
IEEE Applied Power Electronics Conference and Exposition
Pages
558-564
Date Issued
2008-02
Author(s)
Abstract
A constant off-time boost converter with digital control was proposed and implemented with a field-programmable-gate-array (FPGA) to power white light emitting diodes (WLEDs) for hand-held applications. In the application, a lithium-ion battery with voltage ranging from 3.3 V to 4.2 V was used to light a serial connection of 4 WLEDs drawing current levels from 2 mA to 20 mA. A constant off-time digital PWM controller was chosen to increase the dimming resolution. For the compensator design, a small-signal control model for the constant off-time converter was presented. A digital PI compensator with programmable gain was used to stabilize the control loop for different LED current levels. Experimental results are presented. Same design considerations apply to other applications if a digitally-controlled boost or buck/boost converter with high conversion gain is used. ©2008 IEEE.
SDGs
Other Subjects
Digital arithmetic; Digital control systems; Electric converters; Exhibitions; Light emitting diodes; Lithium; Lithium alloys; Pulse width modulation; Applications.; BOOST converters; Compensator design; Control loops; Conversion gains; Current levels; Design considerations; Digital controls; Lithium-ion Batteries; Programmable gain; PWM controllers; Serial connections; Small signals; White LEDs; White light emitting diodes; Power electronics
Type
conference paper