- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2018 24rd International Workshop on Thermal Investigations of ICs and Systems (THERMINIC) - Stockholm, Sweden (2018.9.26-2018.9.28)] 2018 24rd International Workshop on Thermal Investigations of ICs and Systems (THERMINIC) - Structural analysis and modelling of packaged light emitting devices by thermal transient measurements at multiple boundaries
摘要： The paper presents a comprehensive methodology for modeling the electrical, optical, and thermal domains of high-power LEDs, focusing on the XPE2 type from Cree. It introduces optimization algorithms (OPT1 and OPT2) to extract parameters such as series resistance (RS), ideality factor (m), and saturation current (I0) from forward voltage (VF) measurements. A quadratic model for radiant voltage (Vrad) is developed to describe the optical output, and thermal modeling is addressed through structure functions derived from transient thermal measurements. The approach enables accurate prediction of LED performance across varying currents and temperatures, with applications in thermal management and design optimization.
关键词： ideality factor,thermal management,structure function,LED modeling,radiant flux,forward voltage,saturation current,series resistance
更新于2025-09-23 15:23:52
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Experimental study on cooling of high-power laser diode arrays using hybrid microchannel and slot jet array heat sink
摘要： In this study, a hybrid microchannel and slot jet array heat sink is designed and fabricated to achieve a better thermal performance of the high-power laser diode arrays. A standard commercial laser bar with wavelength of 808 nm is packaged on the heat sink and experiments are performed to assess the cooling performance of the hybrid heat sink. In the experiments, the forward voltage method is used to measure the chip temperature and the structure function method is applied to obtain the thermal resistance of the heat sink. Using the deionized water as coolant, the heat sink deals with a heat flux of up to 506 W/cm2 and the thermal resistance of the heat sink is only 0.23 K/W when the flow rate is 0.8 L/min (The average jet velocity is 13.3 m/s). The optical power can be up to 135.5 W corresponding to the wall plug efficiency of 64.2%. Compared with the published solutions related to cooling similar laser chips, the thermal resistance reduces by over 15%, indicating that this hybrid heat sink is an interesting solution to improve the cooling of the high-power laser diode arrays.
关键词： High-power laser diode array,Cooling,Forward voltage method,Thermal resistance,Optical power
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE Industry Applications Society Annual Meeting - Baltimore, MD, USA (2019.9.29-2019.10.3)] 2019 IEEE Industry Applications Society Annual Meeting - LED Power Factor and Quality Factor
摘要： This paper presents the LED power factor and quality factor simply characterized from the available terminal average current, average voltage, and RMS current to evaluate the electric power quality of LEDs. The LED average power is composed of the bandgap power and the resistive power due to the forward voltage and equivalent series resistor in the LED approximate linear circuit, respectively. The forward voltage and equivalent series resistor are characterized from the available terminal average current, average voltage, and RMS current to calculate the bandgap power and the resistive power. The LED power factor and quality factor are calculated from the bandgap power, resistive power and average power to evaluate the electric power quality of LEDs. Using a single-branch LED approximate linear circuit and a high-order LED piece-wise linear circuit, two verification examples, respectively, are demonstrated to calculate their LED power factor and quality factor.
关键词： light-emitting-diode,average power,root-mean-square,average current,forward voltage,resistive power,bandgap power,power factor,rms,LED,quality factor
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 62nd International Midwest Symposium on Circuits and Systems (MWSCAS) - Dallas, TX, USA (2019.8.4-2019.8.7)] 2019 IEEE 62nd International Midwest Symposium on Circuits and Systems (MWSCAS) - Multi-Channel LED Driver with Accurate Current Matching for Portable Applications
摘要： In this paper, we present a multi-string LED driver based on a current-limiting hysteretic boost converter, which is capable of driving ten LEDs in five parallel strings. An accurate current matching circuit with low voltage headroom requirement is implemented to match currents in all LED strings. Dynamic compensation of the LED forward voltage mismatch between the strings is achieved with the introduction of a minimum voltage selector block. A PFM dimming circuit is designed to operate with a 200 kHz clock and has 11 programmable dimming ratios, ranging from 2:1 to 2048:1. This LED driver is implemented in 0.6-μm CMOS process and operates from a Li-ion battery with a voltage range 3 – 4.2 V. It is suitable for backlight LED displays in mobile devices.
关键词： dimming,hysteretic controller,DCM,current matching,LED driver,forward voltage mismatch
更新于2025-09-12 10:27:22