TY - GEN
T1 - A high efficiency LED driver based on optical feedback
AU - Marti-Arbona, Edgar
AU - Copani, Tino
AU - Bakkaloglu, Bertan
AU - Kiaei, Sayfe
N1 - Publisher Copyright:
© 2014 SPIE.
PY - 2014
Y1 - 2014
N2 - Light emitting diodes (LEDs) offer durability, long life, and high efficiency that make them an excellent alternative for illumination applications. The efficiency of conventional drivers suffers from losses due to the current sensing method that they employ. In this paper, the LED array itself is used as an optical sensor by periodically measuring neighboring cells' light intensity, instead of employing the commonly used series current-sense resistor. The results of this approach show that it provides accurate compensation of the LED characteristics, with less than one lumen variation in illumination, stability in color (color shift over time as low as ΔE = 0.76), and efficiency of up to 98.66%. The proposed sensor compensates for actual optical performance of the LED array and reduces aging effects compared to the approaches based in current measurement and control. The optical current-sensing method is a closed-loop feedback alternative, which improves the power efficiency of the LED driver by 3%. It maintains constant output illumination of the LED over time, and it utilizes a reduced number of components, thus extending the effective lifetime of LED-based devices.
AB - Light emitting diodes (LEDs) offer durability, long life, and high efficiency that make them an excellent alternative for illumination applications. The efficiency of conventional drivers suffers from losses due to the current sensing method that they employ. In this paper, the LED array itself is used as an optical sensor by periodically measuring neighboring cells' light intensity, instead of employing the commonly used series current-sense resistor. The results of this approach show that it provides accurate compensation of the LED characteristics, with less than one lumen variation in illumination, stability in color (color shift over time as low as ΔE = 0.76), and efficiency of up to 98.66%. The proposed sensor compensates for actual optical performance of the LED array and reduces aging effects compared to the approaches based in current measurement and control. The optical current-sensing method is a closed-loop feedback alternative, which improves the power efficiency of the LED driver by 3%. It maintains constant output illumination of the LED over time, and it utilizes a reduced number of components, thus extending the effective lifetime of LED-based devices.
KW - Light emitting diode (LED)
KW - Photo-detectors
KW - Pulse width modulation (PWM)
UR - http://www.scopus.com/inward/record.url?scp=84922751148&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84922751148&partnerID=8YFLogxK
U2 - 10.1117/12.2057863
DO - 10.1117/12.2057863
M3 - Conference contribution
AN - SCOPUS:84922751148
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Thirteenth International Conference on Solid State Lighting
A2 - Jiao, Jianzhong
A2 - Kane, Matthew H.
A2 - Dietz, Nikolaus
A2 - Huang, Jian-Jang
PB - SPIE
T2 - 13th International Conference on Solid State Lighting
Y2 - 20 August 2014 through 21 August 2014
ER -