Evaluation of junction temperature of LED package as a function of input current and ambient temperature

2019 ◽  
Author(s):  
Muna E. Raypah ◽  
Mutharasu Devarajan ◽  
Shahrom Mahmoud
Keyword(s):  
Ambient Temperature ◽  
Input Current ◽  
Junction Temperature

Variation of thermal resistance with input current and ambient temperature in low-power SMD LED

2018 ◽  
Vol 35 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Muna E. Raypah ◽  
Dheepan M.K. ◽  
Mutharasu Devarajan ◽  
Shanmugan Subramani ◽  
Fauziah Sulaiman
Keyword(s):  
Low Power ◽  
Thermal Resistance ◽  
Ambient Temperature ◽  
Light Emitting Diode ◽  
Operating Conditions ◽  
Input Current ◽  
Junction Temperature ◽  
Total Thermal Resistance ◽  
Content Type ◽  
Thermal Transient

Purpose Thermal behavior of light-emitting diode (LED) device under different operating conditions must be known to enhance its reliability and efficiency in various applications. The purpose of this study is to report the influence of input current and ambient temperature on thermal resistance of InGaAlP low-power surface-mount device (SMD) LED. Design/methodology/approach Thermal parameters of the LED were measured using thermal transient measurement via Thermal Transient Tester (T3Ster). The experimental results were validated using computational fluid dynamics (CFD) software. Findings As input current increases from 50 to 90 mA at 25°C, the relative increase in LED package (ΔRthJS) and total thermal resistance (ΔRthJA) is about 10 and 4 per cent, respectively. In addition, at 50 mA and ambient temperature from 25 to 65°C, the ΔRthJS and ΔRthJA are roughly 28 and 22 per cent, respectively. A good agreement between simulation and experiment results of junction temperature. Originality/value Most of previous studies have focused on thermal management of high-power LEDs. There were no studies on thermal analysis of low-power SMD LED so far. This work will help in predicting the thermal performance of low-power LEDs in solid-state lighting applications.

Light-emitting diodes as light sources for spectroscopy: Sensitivity to temperature

2017 ◽  
Vol 25 (6) ◽  
pp. 416-422 ◽  
Author(s):  
Clinton J Hayes ◽  
Kerry B Walsh ◽  
Colin V Greensill
Keyword(s):  
Ambient Temperature ◽  
Near Infrared ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Junction Temperature ◽  
Effect Of Temperature ◽  
Light Sources ◽  
Spectral Variation ◽  
Light Emitting ◽  
Full Intensity

Understanding of light-emitting diode lamp behaviour is essential to support the use of these devices as illumination sources in near infrared spectroscopy. Spectral variation in light-emitting diode peak output (680, 700, 720, 735, 760, 780, 850, 880 and 940 nm) was assessed over time from power up and with variation in environmental temperature. Initial light-emitting diode power up to full intensity occurred within a measurement cycle (12 ms), then intensity decreased exponentially over approximately 6 min, a result ascribed to an increase in junction temperature as current is passed through the light-emitting diode. Some light-emitting diodes displayed start-up output characteristics on their first use, indicating the need for a short light-emitting diode ‘burn in’ period, which was less than 24 h in all cases. Increasing the ambient temperature produced a logarithmic decrease in overall intensity of the light-emitting diodes and a linear shift to longer wavelength of the peak emission. This behaviour is consistent with the observed decrease in the IAD Index (absorbance difference between 670 nm and 720 nm, A670–A720) with increased ambient temperature, as measured by an instrument utilising light-emitting diode illumination (DA Meter). Instruments using light-emitting diodes should be designed to avoid or accommodate the effect of temperature. If accommodating temperature, as light-emitting diode manufacturer specifications are broad, characterisation is recommended.

Numerical Study and Experimental Validation of the Thermal Performance for a Parallel Channel Optical Module

2003 ◽  
Author(s):  
Z. F. Shi ◽  
Albert C. W. Lu ◽  
Eric Tan ◽  
Ronson Tan
Keyword(s):  
Ambient Temperature ◽  
Thermal Performance ◽  
Numerical Study ◽  
High Ambient Temperature ◽  
Junction Temperature ◽  
Cavity Surface ◽  
Optical Interconnection ◽  
Laser Array ◽  
Optical Module ◽  
Forced Air

To meet the insatiable demand for data bandwidth in VSR (very short reach up to 300m) applications including server and routers, parallel optical interconnection offers a promising solution in terms of performance and cost effectiveness. A 12-channel pluggable paralle optical transmitter module has been developed to achieve a data rate of 2.5 Gb/s per channel. To maintain the robustness of the optical signal integrity under different environmental conditions, the thermal management is crucial. In this paper the thermal performance evaluation of the optical module was carried out through both numerical simulation and experimental verification. The optical module mainly consists of a VCSEL (vertical cavity surface emitting laser) array, a driver IC and a heat sink. Three types of heat sinks were integrated into the transmitter module separately. The thermal environments used for this evaluation include the normal and high ambient temperature, and both still-air and forced-air conditions. The ambient temperature and the wind speed were controlled by using a Wind Tunnel. The simulation was performed by using a CFD (computational fluid dynamics) program. In all the three modules, the simulation and experimental results of the junction temperature have shown good agreements. For Module 1 under the high ambient temperature, a forced-air condition was required to keep the junction temperature below 70°C. For Module 2 and Module 3, the junction temperature can be controlled below 70°C even under the high ambient temperature without using a fan.

The Study of Comparative Characterization between SiC MOSFET and Si- IGBT for Power Module and Three-Phase SPWM Inverter

2020 ◽  
Vol 1004 ◽  
pp. 1045-1053
Author(s):  
Heng Lee ◽  
Chun Kai Liu ◽  
Tao Chih Chang
Keyword(s):  
Ambient Temperature ◽  
Junction Temperature ◽  
System Level ◽  
Switching Frequency ◽  
Power Module ◽  
Ambient Temperatures ◽  
Three Phase ◽  
Type Power ◽  
Three Phase Inverter ◽  
Better Than

This paper focuses on how to define and integrate the system level and power module level with optimal conditions in SiC and Si-IGBT. To investigate the above situation, we compare the performance of SiC and Si-IGBT in power module and system level at different ambient temperatures. At the same maximum junction temperature 150°C and ambient temperature at 25°C and 80°C, it found that SiC type electrical resistance, maximum endurable current, and voltage could be better than the IGBT type power module above 20%. On the other hand, the simulation of three-phase inverter at different switching frequency such as 10kHz, 15kHz, 20kHz, 30kHz and it had been observed that the power loss of SiC inverter are 78% less for 10kHz switching frequency; 82% less for switching frequency at 15kHz; 85% less for 20kHz of switching frequency; 89% less for switching frequency at 30kHz in the Si-IGBT three-phase SPWM inverter at ambient temperature 80°C.

scholarly journals Accurate Determination of Junction Temperature in a GaN-Based Blue Light-Emitting Diode using Nonlinear Voltage-Temperature Relation

2021 ◽  
Author(s):  
Chibuzo Onwukaeme ◽  
Won-Jin Choi ◽  
Han-Youl Ryu
Keyword(s):  
Ambient Temperature ◽  
Blue Light ◽  
Accurate Determination ◽  
Quadratic Function ◽  
Junction Temperature ◽  
Nonlinear Dependence ◽  
Quadratic Model ◽  
Temperature Relation ◽  
Light Emitting

Abstract We investigate the junction temperature measurements for GaN-based blue light emitting diodes (LEDs) using nonlinear dependence of the forward voltage ( V f ) on temperature. Unlike the conventional linear model of the dependence of V f on temperature, the modeling of the temperature dependent V f with a quadratic function showed good agreements with measured data in the temperature range between 20 and 100 o C. Using the proposed quadratic model, the junction temperature and thermal resistance of the measured LED could be accurately determined as the ambient temperature varied. It was observed that the junction temperature increment remained almost unchanged as the ambient temperature increased from 20 to 80 o C, which could be attributed to the interplay between the decrease in series resistance and the increase in non-radiative recombination with increasing temperature. The presented method for accurate determination of the junction temperature is expected to be advantageously employed for the thermal management of high-power LEDs.

A High Temperature Linear Wideband Power Amplifier for a Downhole Communication System

2017 ◽  
Vol 2017 (HiTEN) ◽  
pp. 000114-000117
Author(s):  
S. Reza Hiemstra ◽  
Brannon M. Kerrigan ◽  
Dong S. Ha
Keyword(s):  
Ambient Temperature ◽  
Power Amplifier ◽  
Communication System ◽  
Oil And Gas ◽  
Maximum Output Power ◽  
Oil And Gas Industry ◽  
Junction Temperature ◽  
Maximum Output ◽  
Gas Industry ◽  
Power Added Efficiency

Abstract In order to reach previously untapped wells, the oil and gas industry continues to drill deeper, resulting in extreme operating temperatures for electronic systems. It is essential for electronic circuits and systems to be able to withstand extreme temperatures. The proposed power amplifier (PA) intends for a downhole communication system operating at an ambient temperature of 230 °C. The proposed PA is designed with Qorvo T2G6003028-FL GaN on SiC HEMT, which offers a high junction temperature. The proposed PA can operate reliably up to an ambient temperature of 230 °C with the operation frequency from 228 MHz to 263 MHz. At 230 °C, it achieves maximum output power of 1.66 W, the peak gain of 24 dB, peak PAE (power added efficiency) of 25%, OP1dB (output 1-db compression point) of 32 dBm, and OIP3 (output third intercept point) of 37.9 dBm..

Transistor Resizing Based Low Power Thermal Aware Adder Design on FPGA

2015 ◽  
Vol 1098 ◽  
pp. 37-43
Author(s):  
Kartik Kalia ◽  
Khyati Nanda ◽  
Arushi Aggarwal ◽  
Akshita Goel ◽  
Shivani Malhotra
Keyword(s):  
Thermal Analysis ◽  
Ambient Temperature ◽  
Heat Sink ◽  
Energy Efficient ◽  
Leakage Power ◽  
Junction Temperature ◽  
Efficient Technology ◽  
Scale Down ◽  
Energy Efficient Technology ◽  
Target Design

In this work, we are going to search the most thermal and energy efficient technology among 90nm, 65nm, 45nm, 40nm and 38nm technology based FPGA, and also searching the most thermal and energy efficient airflow, and heat sink profile. We are also doing thermal analysis for 273.15K-343.15K temperature. we are getting 31.67%, 75.71%, reduction in leakage power for 250LFM and 58.53%, 75.71% reduction in leakage power for 500LFM when we scale down ambient temperature from 343.15K to 283.15K for 65nm, 28nm technology based FPGA. There is 84.54%, 85.65%, reduction in junction temperature for 250LFM, 84.90%, 85.65%, reduction in junction temperature for 500LFM when we scale down ambient temperature from 343.15K to 283.15K for 65nm, 28nm technology based FPGA. In this work, we are using 90nm Spartan-3E FPGA, 65nm Virtex-5 FPGA, 45nm Spartan-6 FPGA, 40nm Virtex-6 FPGA, and 28nm Artix-7 FPGA. We are taking two different airflow of 250LFM and 500LFM. LFM is a unit of airflow. LFM is linear feet per minute. Adder is our target design.

Ambient Temperature and Self-Heating Scaling Laws for Materials With Temperature-Dependent Thermal Conductivity

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
John Ditri
Keyword(s):  
Ambient Temperature ◽  
Material Properties ◽  
Power Dissipation ◽  
Scaling Laws ◽  
Scaling Law ◽  
Junction Temperature ◽  
Base Temperature ◽  
Temperature Dependent ◽  
Self Heating ◽  
Simple Scaling

Two of the primary variables affecting junction temperature of semiconductor devices are the self-heating due to internal power dissipation within the device and the device's base (or ambient) temperature. For materials with temperature-independent material properties, the junction temperature is a linear function of these two variables, which allows for simple “scaling” of the junction temperature for arbitrary dissipation and/or base temperatures. In materials with temperature-dependent material properties, however, the relationship between junction temperature and either variable is nonlinear. The scaling law between junction temperature and dissipated power and base temperature for materials with temperature-dependent material properties are developed in this work. This scaling law allows for fast computation of junction temperature for any values of power dissipation and/or base temperature given the junction temperature for one specific instance of power dissipation and base temperature and hence may find applicability in fast electrothermal solvers.

Thermal Mechanics Based Energy Efficient FIR Filter for Digital Signal Processing

2014 ◽  
Vol 612 ◽  
pp. 65-70 ◽  
Author(s):  
Bishwajeet Pandey ◽  
Tanesh Kumar ◽  
Teerath Das ◽  
S.M.M. Islam ◽  
Jagdish Kumar
Keyword(s):  
Ambient Temperature ◽  
Power Dissipation ◽  
Energy Efficient ◽  
Digital Signal ◽  
Fir Filter ◽  
Leakage Power ◽  
Junction Temperature ◽  
High Profile ◽  
Thermal Mechanism ◽  
Leakage Power Dissipation

Thermal mechanism cover the mechanics of Hit Sink, Airflow mechanics, and Ambient Temperature Mechanism to reduce junction temperature in design of Finite Duration Impulse Response (FIR) Filter. In this work, we are implementing FIR Filter on 28nm FPGA. After implementation of FIR Filter, we analyze the effect of in-built mechanism of Air Flow Controller and their produced Airflow on the junction temperature of FPGA. The mechanism of Ambient Temperature controller also play significant role in leakage power dissipation as well as junction temperature of FPGA. Finally, the mechanical structure of Hit Sink is considered for control of junction temperature of FPGA. There is 73.38% reduction in Leakage Power on 55 C ambient temperature when we increase airflow from 250 LFM to 500 LFM. Along with 500 LFM airflow, if we provide high profile hit sink then there is 78.31% reduction in leakage power. There is 37.68% reduction in junction temperature of FPGA when we increase airflow from 250LFM to 500LFM. Along with 500 LFM airflow, if we provide high profile hit sink then there is 41.76 % reduction in junction temperature on 45C ambient temperature. There is no effect of airflow on clock power. Whereas there is significant reduction in Logic Power, Signal Power, DSPs Power and IOs Power with change in Airflow.

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