Design and Verification of a High Performance LED Driver with an Efficient Current Sensing Architecture

Jin He, Wing Yan Leung, Tsz Yin Man, Lin He, Hailang Liang, Aixi Zhang, Qingxing He, Caixia Du, Xiaomeng He, Mansun Chan

Department of Electrical and Electronic Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, China.
Peking University, Shenzhen SOC Key Laboratory, PKU HKUST Shenzhen Institution, Shenzhen Institute of Peking University, Shenzhen, China.
Peking University, Shenzhen SOC Key Laboratory, PKU HKUST Shenzhen Institution,Shenzhen Institute of Peking University, Shenzhen, China; Shenzhen Huayue Terascale Chip Ltd. Co., Shenzhen, China.
Peking University, Shenzhen SOC Key Laboratory, PKU HKUST Shenzhen Institution,Shenzhen Institute of Peking University, Shenzhen, China;Department of Electrical and Electronic Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, China.
Shenzhen Huayue Terascale Chip Ltd. Co., Shenzhen, China.

DOI: 10.4236/cs.2013.45052                

Abstract

A high power buck-boost switch-mode LED driver delivering a constant 350 mA with a power efficient current sensing scheme is presented in this paper. The LED current is extracted by differentiating the output capacitor voltage and maintained by a feedback. The circuit has been fabricated in a standard 0.35 μm AMS CMOS process. Measurement results demonstrated a power-conversion efficiency over 90% with a line regulation of 8%/V for input voltage of 3.3 V and current output between 200 mA and 350 mA.

Keywords

LED Driver; Current Sensing; Capacitor Voltage; Feedback; Circuit

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Philips Lumileds Lighting Company, “Philips Lumileds LED Technology Breakthrough Fundamentally Solves Efficiency Losses at High Drive Currents,” Press Infor mation, Philips Lumileds Lighting Company, San Jose, 2007.
[2]	Linear Technology Corporation, “1A Synchronous Buck Boost High Current LED Driver,” Datasheet LTC3454, Linear Technology Corporation, Milpitas, 2005.
[3]	Maxim Integrated Products, “Offline and DC-DC PWM Controllers for High Brightness LED Drivers,” Datasheet MAX 16802, Maxim Integrated Products, San Jose, 2006.
[4]	LLC, “NCP5030: Buckboost Converter to Drive a Single LED from 1 Li-Ion or 3 Alkaline Batteries,” Datasheet NCP 5030, Rev. 0, Semiconductor Components Indus tries, LLC, Denver, 2006.
[5]	Maxim Integrated Products, “1.5MHz, 30A, High-Effi ciency LED-Driver with Rapid Current Pulsing,” Data sheet MAX 16818, Maxim Integrated Products, San Jose, 2006.
[6]	Texas Instrument Incorporated, “Synchronous Boost Con verter with Down Mode High Power White LED Driver,” Datasheet tps61058/tps61059, Texas Instrument Incorpo rated, Dallas, December 2005.
[7]	National Semiconductor, “1.2A High Power White LED Driver, 2MHz Synchronous Boost Conveter with I2C Compatible Interface, Constant Current Buck Regulator for Driving High Power LEDs,” Datasheet LM 3402, Na tional Semiconductor, Santa Clara, 2006.
[8]	W. Y. Leung, T. Y. Man and M. Chan, “A High-Power LED Driver with Power-Efficient LED-Current Sensing Circuit,” 2008 European Solid-State Circuits Conference, Edinburgh, 15-19 September 2008, pp. 354-357.
[9]	McClelland, Schafer and Yoder, “Signal Processing First,” Prentice Hall Inc., New Jersay, 2003, pp.71-79.
[10]	W. H. Ki, “Signal Flow Graph in Loopgain Analysis of DC-DC PWM CCM Switching Converters,” IEEE Tran sactions on Circuit and System I: Fundamental Theory and Applications, Vol. 45, No. 6, 1998, pp. 664-655.