Analysis and design of a multi‐channel constant current light‐emitting diode driver based on high‐frequency AC bus

In the last decade, silicon carbide (SiC) has gained a remarkable position among wide bandgap semiconductors due to its high temperature, high frequency, and high power electronics applications. SiC heterostructures, based on the most prominent polytypes like 3C-SiC, 4H-SiC and 6H-SiC, exhibit distinctive electrical and physical properties that make them promising candidates for high performance optoelectronic applications. The results of simulations of nn-junction 3C-4H/SiC and 6H-4H/SiC heterostructures, at the nanoscale and microscale, are presented in this paper. Nanoscale devices are simulated with QuantumWise Atomistix Toolkit (ATK) software, and microscale devices are simulated with Silvaco TCAD software. Current-voltage (IV) characteristics of nanoscale and microscale simulated devices are compared and discussed. The effects of non-ideal bonding at the heterojunction interface due to lattice misplacements (axial displacement of bonded wafers) are studied using the ATK simulator. These simulations lay the groundwork for the experiments, which are targeted to produce either a photovoltaic device or a light-emitting diode (working in the ultraviolet or terahertz spectra), by direct bonding of SiC polytypes.

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Degradation behavior of high power light emitting diode under high frequency switching

Microelectronics Reliability ◽

10.1016/j.microrel.2012.06.069 ◽

2012 ◽

Vol 52 (9-10) ◽

pp. 2168-2173 ◽

Cited By ~ 3

Author(s):

S.H. Chen ◽

C.M. Tan ◽

G.H. Tan ◽

F.F. He

Keyword(s):

High Power ◽

High Frequency ◽

Light Emitting Diode ◽

Degradation Behavior ◽

Light Emitting

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LIGHT EMITTING DIODE DRIVERS AND CONTROL

International Journal of High Speed Electronics and Systems ◽

10.1142/s0129156411006593 ◽

2011 ◽

Vol 20 (02) ◽

pp. 267-286

Author(s):

STEVE WINDER

Keyword(s):

Light Emitting Diode ◽

Current Source ◽

Constant Current ◽

Constant Current Source ◽

Basic Principles ◽

Light Emitting ◽

Control Techniques ◽

Switching Regulator ◽

Step Down ◽

And Control

This paper outlines the various driving and control techniques for Light Emitting Diodes (LEDs). LEDs should be driven from a constant current source. High power LEDs are usually driven from a switching regulator, for reasons of efficiency. The types of drivers described include Buck (step-down), Boost (step-up) and Buck-Boost (step-up or step-down). Isolated drivers and Power Factor Correction (PFC) circuits are also described. This brief paper can only describe the basic outline of these circuits, but this should be sufficient to allow the basic principles to be understood.

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Macroscopic Coulomb-blockade effect in a constant-current-driven light-emitting diode

Physical Review B ◽

10.1103/physrevb.52.2008 ◽

1995 ◽

Vol 52 (3) ◽

pp. 2008-2012 ◽

Cited By ~ 23

Author(s):

Jungsang Kim ◽

Hirofumi Kan ◽

Yoshihisa Yamamoto

Keyword(s):

Coulomb Blockade ◽

Light Emitting Diode ◽

Constant Current ◽

Light Emitting

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Thermal Performance of LED Filament in Flip-Chip Packaging Manufactured for Different Correlated Color Temperature

Applied Sciences ◽

10.3390/app11198844 ◽

2021 ◽

Vol 11 (19) ◽

pp. 8844

Author(s):

He Jiang ◽

Jiming Sa ◽

Cong Fan ◽

Yiwen Zhou ◽

Hanwen Gu ◽

...

Keyword(s):

Thermal Performance ◽

Flip Chip ◽

Heat Dissipation ◽

Light Emitting Diode ◽

Color Difference ◽

Junction Temperature ◽

Color Temperature ◽

Constant Current ◽

Light Emitting ◽

Flip Chip Packaging

The effect of correlated color temperature (CCT) on the thermal performance of light emitting diode (LED) filament in flip-chip packaging was investigated in detail. Two filaments with different lengths were selected as the research object, and the thermal resistance of filaments under three CCT (2200 K, 2400 K, 2700 K) were studied. The optical properties and thermal parameters of the two groups of filaments were measured, and the results were analyzed combined with the color coordinate. The experimental results show that thermal properties of LED filaments is closely related to CCT. Under constant current condition, junction temperature decreases with the increase of color difference. With the change of phosphor glue and phosphorus powder ratio, the color temperature of LED filament also changes. In the filaments with the same chip structure and packaging mechanism, the higher the proportion of red phosphorescent powder, the worse the heat dissipation performance of the filament. These results show that in the design and manufacture of LED filament, it is helpful to control the CCT of LED filament under the premise of meeting the use requirements.

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