ESC

LEDs

Lee Goldberg
Principal
Information on LEDs (light emitting diodes) and their various applications that runs the gamut from individual LED components to LED light teardowns, as well as in-depth technical design articles, regulatory and industry news, and product features.

LED Lady, Rumblings of China LED industry shakeout , Metal-free OLEDs on the horizon

In this week's Semi-Coherent Emissions we welcome Lindsay Wood, aka "The LED Lady" as this section's first V-blogger. Also as the latest Chinese LED manufacturer to close its doors signals some "interesting times" ahead. Read More...

IoT-ready Smart Lighting manager ICs feature integrated daylighting, spectral management and multi-sensor support.

Ams's new Smart lighting manager ICs support network-commanded dimming, daylighting and other basic smart lighting functions as well as an autonomous mode which only relies on a local or remote host for configuration and exception handling. Unlike most of their counterparts, they have highly-accurate built-in light sensors which enable precise daylighting, lumen maintenance, and in the case of the AS7221, color tuning. In addition, the same sub-$10 solution that drives the lighting system can also serve as a low-cost platform for many other Smart Building services. Read More...

Parallel Operation Minimizes Temperature Rise in Synchronous 4-Switch Buck-Boost Converters

A single synchronous buck-boost DC/DC converter can deliver high power due to its synchronous switching topology, but eventually the switching and/or conduction losses at higher power can overwhelm a single converter with excessive board heating. Although heat can be mitigated with bulked up heat sinks, additional external gate drivers, and/or forced airflow, it may be better to simply tie together two or more converters in parallel to spread the load. This is easy to do with the LT3790 4-switch synchronous buck-boost DC/DC converter. Read More...

The Hat at Maker Faire - Day 1

The Hat's had a busy time at the first day of the Maker Faire. Between watching high-powered kiddie car races, performing for visitors, and helping build mini-Smart Hats, there was barely enough time to get out of the booth to see a few sights. And wondrous sights they were indeed! Read More...

Greetings from Maker Faire 2015

One half embedded development platform, one half photonic fashion statement, and 100% attitude, Editor Lee Goldberg's "Smart Hat" is on its first solo assignment: report on some of the DIY activities at the Bay Area Maker Faire. Read More...

Celebrate DIY Victorian high-tech at the Steampunk World's Fair

It's time to dust off your goggles, charge up your ray gun and set your airship's course for the Steampunk World's Fair. Held May 15-17 in Piscataway, New Jersey, the fair is a Mecca for DIY-ists who take a somewhat unique approach to technology, fashion, and alternate history. Read More...

Smart vs. Fart Lighting, wood-powered LEDs and levitating lightbulbs?

Lightfair is full of surprises, including a heat-powered LED lantern and a Smart Lighting System with a sense of smell. And has "Smart Lighting" become the lamest buzzword of the year? Read More...

Reducing cost & complexity of LCD LED backlights with single-IC, single-inductor multi-string LED driver architectures

In his fourth installment we'll look a single-IC, single-inductor multi-string LED driver architectures which provide great savings in both solution cost and PCB real estate. For this tutorial, we'll use the LT3598 which can drive up to six strings of ten LEDs at up to 30mA per string and a built-in power switch. Read More...

Meet me at Lightfair - Meet my Smart Hat at Maker Faire!

If you are attending Lightfair on May 5th or 6th, please join me for coffee, industry gossip, and a healthy dose of geek fellowship at EDN's Reader/Editor Meet-Up. Normally, I'd be very easy to spot because I'd be wearing my Smart Hat, but this time I'll be a bit harder to pick out of the crowd. That's because The Hat is on its way to the Maker Faire. Read More...

EDN field-tests the ultimate LED party lights

BlissLights makes some seriously cool toys. When I gave a brief shout-out to them in a recent Semi-coherent Emissions blog I knew I had to get my hands on a couple of these grown-up party bulbs. Happily, BlissLights cheerfully loaned me a few of their photonic toys so I could subject them to a little real-world testing at my St. Patrick's Day party. Read More...

LED light guides deliver affordable OLED-like performance

Sleek, stylish and seductively luminous, OLED panels' silky, eerily-even glow has made them a favorite for fashion-forward lighting designers, even though they cost more, were shorter lived, and more easily damaged. This may change however, as Global Lighting Technologies' (GLT) introduces a growing number of products based on its edge-lit LED-based light guide technology. Read More...

LEDs battle ebola and climate change while boosting the economy

This week's Semi-Coherent Emissions top story: The LED lighting industry's performance provides compelling evidence that strong economic growth and high environmental quality aren't mutually-exclusive. Read More...

Powering LED Lighting & Other Illumination Devices: Part 3

This third installment of a multi-part series on design issues in LED lighting explores the capabilities of the LT3799, a high-power factor, self-isolated, TRIAC-compatible LED driver. It includes several practical examples of how these properties can be used to solve common design issues for LED applications in a simple, cost-effective manner. Read More...

Powering LED Lighting & Other Illumination Devices: Part 2 (Updated)

This second installment of a multi-part series includes several practical examples based on the LT3791 is a 4-switch synchronous buck-boost DC/DC converter that regulates both constant-current and constant voltage at up to 98.5% efficiency with a single inductor. Read More...

Air Force reveals its new aircraft cloaking system uses dark-emitting diodes (DEDs)

Star Trek has finally met its match in real life with the U. S. Air Force’s revelation of a new stealth technology based on dark-emitting diodes (DEDs). Read More...

Zener-enhanced Dark Emitting Diodes (ZeDEDs) deliver 10X more Dark per Watt

YoYo Dyne Systems' new family of Zener-enhanced dark-emitting diodes (ZeDEDs) features a novel junction structure and an integrated light sink to achieve a 10X boost in performance over equivalent-sized conventional darkness emitters. Read More...

>> SEE ALL

HB-LED flashing beacon repurposes switching regulator

A classic, low-cost “switcher” IC is repurposed to flash a high-brightness LED in this minimal-parts-count Design Idea. Read More...

Two PIC pins drive six LEDs

Here’s a take on LED multiplexing with minimal output pins. Read More...

Failsafe multichip LED module driver

Keep a power LED module with multiple strings operating despite fault conditions. Read More...

Design Notes: 60V, Synchronous Step-Down High Current LED Driver

Highly efficient high-power LED controller/driver also facilitates MPPT. Read More...

H-bridge paves new ways for LED lighting

Drive a LED array directly from the AC mains in full-wave current-limited mode to realize a flicker-free, energy-efficient solid-state lamp. Read More...

Pocket white-LED torch is power efficient

This single white-LED torch can be housed in an empty glue-stick tube and has a long rechargeable-battery life. Read More...

An improved offline driver lights an LED string

Keep the current constant and the voltage low for improved power efficiency. Read More...

Photo meter assesses ambient light

When most PN-junction diodes are reverse biased, they will produce a small photovoltaic output as the light level is increased. Read More...

Use an LED matrix horizontally

Using one 5×7 LED matrix horizontally instead of vertically allows the display of two characters instead of one. Read More...

Eight LEDs make a 100-division voltmeter

Use a counter IC to drive two sets of four LEDs. Read More...

>> SEE ALL

IoT-ready Smart Lighting manager ICs feature integrated daylighting, spectral management and multi-sensor support.

Ams's new Smart lighting manager ICs support network-commanded dimming, daylighting and other basic smart lighting functions as well as an autonomous mode which only relies on a local or remote host for configuration and exception handling. Unlike most of their counterparts, they have highly-accurate built-in light sensors which enable precise daylighting, lumen maintenance, and in the case of the AS7221, color tuning. In addition, the same sub-$10 solution that drives the lighting system can also serve as a low-cost platform for many other Smart Building services. Read More...

EDN field-tests the ultimate LED party lights

BlissLights makes some seriously cool toys. When I gave a brief shout-out to them in a recent Semi-coherent Emissions blog I knew I had to get my hands on a couple of these grown-up party bulbs. Happily, BlissLights cheerfully loaned me a few of their photonic toys so I could subject them to a little real-world testing at my St. Patrick's Day party. Read More...

DC/DC converter drives high-power LEDs

Outfitted with an internal 60-V, 4-A DMOS power switch, the LT3952 current-mode DC/DC converter from Linear Technology can drive up to 16 350-mA white LEDs from a nominal 12-V input, delivering in excess of 15 W. Read More...

LED light guides deliver affordable OLED-like performance

Sleek, stylish and seductively luminous, OLED panels' silky, eerily-even glow has made them a favorite for fashion-forward lighting designers, even though they cost more, were shorter lived, and more easily damaged. This may change however, as Global Lighting Technologies' (GLT) introduces a growing number of products based on its edge-lit LED-based light guide technology. Read More...

LEDs battle ebola and climate change while boosting the economy

This week's Semi-Coherent Emissions top story: The LED lighting industry's performance provides compelling evidence that strong economic growth and high environmental quality aren't mutually-exclusive. Read More...

Zener-enhanced Dark Emitting Diodes (ZeDEDs) deliver 10X more Dark per Watt

YoYo Dyne Systems' new family of Zener-enhanced dark-emitting diodes (ZeDEDs) features a novel junction structure and an integrated light sink to achieve a 10X boost in performance over equivalent-sized conventional darkness emitters. Read More...

Wireless-enabled LED lighting drivers reduce product integration and deployment costs

By embracing Daintree's philosophy of developing control systems that support open standards, LG is also encouraging development of innovative and affordable products. Read More...

Step-down driver furnishes up to 40 A of LED current

The LT3744 synchronous step-down DC/DC converter from Linear Technology delivers constant current to drive high-current LEDs, while its 3.3-V to 36-V input voltage range accommodates a wide variety of applications, including industrial, DLP (digital light processing) projection, and architectural lighting. Read More...

15W TRIAC-dimmable, Energy Star-compliant LED drivers work smoothly with nearly any dimmer

Although Phihong USA's new series of 15W TRIAC-dimmable constant current LED drivers sacrifices some efficiency and power quality performance for the sake of compatibility and cost, the drivers are still worth considering for many applications. Read More...

Pint-sized printer delivers pro-quality 3D performance at entry-level price point

Priced at $1,350, Aleph Objects' LulzBot Mini offers a combination of versatility, precision and ease which puts it on the (very) short list of entry-level printers I'd recommend to both tech-savvy DIY-ers and the growing number of consumers who are considering buying their first 3D printer. Read More...

Dual-protocol wireless control modules enable smart, networked LED drivers, luminaires, bulbs, and wall plugs

The first two implementations of the dual-protocol platform are a multi-mode (0-10V or DALI) Bluetooth lighting controller and a Class 2 embedded Bluetooth 4.0 module. They can be integrated into lighting fixtures, LED drivers, and LED smart bulbs. Both the Bluetooth controller and lighting module are programmed to automatically form a self-healing and self-organizing wireless mesh network with any other Casambi-enabled devices within "earshot" of it. Each device can also be paired to a Bluetooth Smart Ready smartphone or tablet, enabling any fixture within the mesh to be controlled from any other point without the need for an external gateway module. Read More...

¼-size Arduino board packs full-size punch + on-board LiPo charge/mgmt

Despite its compact 1in x 1.5in form factor, the Qduino Mini board packs all the punch of its full-sized counterparts and throws in a turnkey battery fuel gauge and charger just for grins. Read More...

LED lighting aspects in parking structures

Many people do not realize the effect that lighting can have on the human experience. Read More...

Inspection system checks LED color and intensity

EVT has devloped the EyeSens MCI multi-color inspection system for measuring objects for color and intensity with the integrated EyeVision image processing software. Read More...

Networked, color-tunable troffer makes high-quality lighting affordable, easy to install

Although I have a few unresolved issues regarding its SmartCast wireless control technology, I'm posting this review because Cree's new Troffer is one of the first commodity-level products I've seen which makes a respectable attempt at realizing solid-state lighting technology's full potential instead of simply being a more efficient light bulb. Read More...

Wi-Fi equipped 32-bit Arduino board streamlines cloud-powered embedded app development

Digilent's chipKIT WiFire board is an awesome little beastie. Powered by Microchip's powerful 32-bit 200 MHz MCU, the Wi-Fi equipped Arduino-compatible platform has been paired with Imagination Technologies' Flow Cloud service development tools in an effort to make creating cloud-powered embedded applications practical for the average developer. Read More...

Compact high-output LED module enables innovative designs for theatrical-type lighting equipment

Osram's Ostar Stage multi-element LED's high output and compact form factor of the 4-LED (RGBW) module which could be just what designers need to create a new generation of affordable, efficient, lighting products for theatrical, exhibition and architectural applications. Read More...

ZigBee 3.0 radio chips and modules can add Smart Home/IoT capabilities to lighting applications

GreenPeak Technologies' GP691 communication controller chip and GPM6000 integrated Modules provide a much-needed solution for implementing ZigBee 3.0, Thread, and other advanced wireless protocols. Read More...

Intelligent four-channel LED driver offers design flexibility

Code Mercenaries has introduced a 4-channel, intelligent, programmable LED driver which has I2C, DMX512, and DALI interfaces. Read More...

Arduino LED controller shield makes complex RGB LED lighting apps a snap

The Arduino-compatible lighting RGB LED lighting shield reviewed here was designed to give designers a low-cost easy-to-use open-source platform for fast prototyping and inexpensive evaluation of multiple LED light engines. Read More...

Cloud-based Smart Building system enables genius-level Smart Lighting

Daintree Networks' subscription-based cloud application provides a full suite of building and energy management services including genius-level Smart Lighting capabilities. Read More...

Two-string HB automotive LED driver provides 10000:1 dimming ratio

For use in automotive display backlights, automotive lighting applications and LCD backlights, Maxim has posted detail of the MAX16838B which it says is the only-available 2-String HB LED driver providing 10000:1 dimming ratio. Read More...

Triple LED controllers for rear lights

The IC family E522.80/81/82/83 from Elmos AG is an LED controller device, designed for applications like automotive rear lights. The devices offer three channels each, with a maximum current of 140 mA. Read More...

Advanced thermal imager cuts LED test time by 90+%

Known as an In-Line Compact Thermal Analyzer (ICTA), MPI's new testing system uses high-resolution thermal imaging and a newly-developed high-speed temperature sensitive parameter (TSP) measurement technique which promises to reduce LED testing time by more than 90 percent. Read More...

EDN Hot 100 products of 2014: Power & Optoelectronics/Lighting Control

This section of EDN's Hot 100 Products of 2014 includes power-related devices and ICs, as well as LEDs and optoelectronic/lighting control devices. Read More...

Multi-LED matrix manager enables simpler, lower-cost adaptive headlights

TI's TPS92661-Q1 LED matrix manager is a is welcome (and well-timed) entry into the automotive electronics market because it will help designers address some of the important technical and economic challenges associated with LED-based headlights. It's also likely that the elements which enable the device to precisely control up to 96 high-brightness LEDs will help find it applications beyond its intended market in many non-automotive lighting products. Read More...

High-temp-high-power LEDs may enable lower solution costs for lamps & light engines

Cree's XLamp MH-B LED series reflects an interesting strategy for helping manufacturers control their total component costs without having to slash too deeply into Cree's part of the BOM. Besides making it easy for manufacturers to cut assembly costs by moving from large arrays of mid-power LEDs to fewer, higher-powered LEDs, Cree says that their MH-B devices' higher operating temperatures enable designers to use smaller, lighter heat sinks which dramatically reduce product's total BOM cost. Read More...

Littlefuse announces circuit-protection at Electronica

The company is also announcing LED circuit protection, reed-sensing devices, and thyristors. Read More...

8000 Lumen LED module unveiled by Cree

The Cree LMH2 8000 lumen LED module is an industry first. The solution, designed for high-ceiling applications, easily replaces and actually obsoletes 150-watt ceramic metal halide (CMH) lamps. Read More...

3D printed optics for outdoor and indoor LED lighting designs

LUXeXceL's high-resolution 3D printing process avoids the optical flaws created by the individual layers filament-based machines produce. Instead, they use something similar to an ink jet printer which deposits micro drops of a photopolymer onto a substrate material and hardens them with UV light. Read More...

Track and recessed LED luminaires offer adjustable benefits

Intense Lighting Inc. has released the MX family of LED recessed multiples and track luminaires which provide adjustability, high performance and efficiency suited for accent and spot lighting applications such as retail, museums and galleries. Read More...

LED-fitted passive RF-field detector tag offers visual feedback

Equipped with a bright LED, whenever Farsens' Photon RFID tag comes close to an RF field source, it harvests energy from the RF field and drives its LED according to the field’s strength. Read More...

Color sensor tunes LED light color through smartphone interface

Through the use of its True Color sensor, MAZeT GmbH has demonstrated the accurate colour control of LEDs using a smartphone or tablet as a remote control. Read More...

LED lighting design sites offer tips, tools and techniques to speed design

ON Semiconductors has launched a pair of web sites which put you one click away from a bunch of resources which could be valuable for your next LED lighting design. They've mined a lot of their deep expertise in power and analog, and applied it directly to LED-related issues in the form of design notes, app notes, white papers and videos. Read More...

Buck/boost converter drives dimmable LEDs

The AL8812 DC/DC converter from Diodes Inc. contains an internal temperature-compensated reference, comparator, controlled duty-cycle oscillator with an active current-limit circuit, driver, and high-current output switch for driving dimmable MR16 LED lamps. Read More...

LED light engines’ hybrid packaging helps cut cost of PAR & halide replacements with longer life, wider design options

Bridgelux’s V10 and V15 light engines should make a lot of lighting equipment designer’s jobs easier – and probably more fun. These compact, high-performance Chip-on-Board (COB) LED array light sources bring all the advantages of the higher-powered members of the V-series product family (introduced last September) to many mid-power applications. Read More...

LEDs offer almost natural sunlight colour spectrum

Kyocera Corporation has developed a new type of LED that produces a color spectrum close to natural sunlight which makes the device ideal for color-inspection applications. Read More...

LED system enables instant customization of PAR30, PAR38 and AR111 lamps

SORAA’s s SNAP System of rapidly-customizable LED lamps now includes several large lamp products and accessories which allow users to customize light directly on the lamp rather than on the fixture. Read More...

Isolated LED-Driver ICs Offer Higher Output & Efficiency, Greater Dimming Accuracy, Lower Component Count

LYTSwitch-2 family of isolated LED drivers from Power Integrations delivers up to 12 watts of accurately controlled output power while enabling simpler, smaller, more reliable and more cost-effective LED lighting designs. Read More...

Rectangular, low profile LED opens up design options

The Synios E4014 LED from Osram Opto Semiconductors features a rectangular and low profile shape so that, with the design, light is easily injected into light guides and uniformly distributed. Read More...

Flush-mountable IR LED delivers remote control functionality

Osram Opto Semiconductors has introduced the company's first flush-mountable infrared LED which enables remote control functionality to be incorporated in a lower profile than ever before. Read More...

Mid- & Hi-Power LED drivers feature on-chip PFC, thermal/electrical protection

On Semiconductors' new series of power factor corrected (PFC) offline AC-DC LED drivers bring the same high levels of integration and application-specific features usually found only in lower-powered drivers to mid- and high-power SSL applications. Read More...

Free PCB design tool includes 3D modeling, crowd-sourced parts database

CircuitMaker PCB design tools' 3D modeling and other features will help designers deal with the "lumpy" nature of LED lighting products or other design projects involving large, irregular components. But that's only half of the story. Read More...

Chip-scale packaged LEDs offer new options for designers, more Lumens/$

If SemiLEDs' claims measure up, the new packaging option should give light-engine and luminaire manufacturers a more flexible and potentially more cost-effective alternative to the packaged die solutions they use today. Read More...

Heave your heat sinks with Bergquist's "Thermal Management for LEDs" guide

One of the ugly truths of the SSL industry is that conventional heat sinks often account for a shockingly high percentage of many LED products' BOM and assembly costs. That's why I was so intrigued when I stumbled on a copy of Bergquist's solutions guide for using their T-Clad thermal substrates in LED designs Read More...

Integrated display power and LED driver IC for Smartphones

What designer could say no to a device which saves them precious board space while adding much-needed slack to their power budget? And the hybrid dimming capability is icing on the cake. Read More...

IR LED achieves 48% electro-optic efficiency

Intended for security illumination, the Oslon Black SFH 4715A infrared LED from Osram Opto Semiconductors offers a typical electro-optic efficiency of 48%, as well as a 90° beam angle and a 30% increase in output power over its predecessor, the SFH 4715. Read More...

UVLEDs’ improved AlN substrate helps deliver longer life, cleaner spectrum for scientific & industrial instruments

Crystal IS says that the properties of their proprietary native Aluminum Nitride (AIN) substrate allows them to create UVC LED structures which provide a precise, energy-efficient light source that can be used in a wide variety of spectroscopic equipment, including analytical and life sciences instrumentation, as well as environmental monitoring. Read More...

>> SEE ALL

What's inside the Samsung 40W-replacement-LED light?

What's inside the Samsung 40W-replacement-LED light? Read More...

Remote phosphor expands reach of LED light

This Prying Eyes explores how an LED bulb is able to project light in an almost 360-degree pattern. Read More...

Visionaire Lighting’s Solar Vision Pole: shedding light on off-grid lampposts

Certain applications justify paying a premium for high efficiency, long life, ruggedness, and light-color-temperature control, and these applications represent the sweet spot for HB LEDs (high-brightness light-emitting diodes). Read More...

Compact fluorescent lights: Not always the best solution

Prying Eyes: A look inside a CFL bulb helps explain why they're no good in downward-facing installations. Read More...

Way, way off the grid: Powering the Phoenix Mars lander

Prying Eyes: An inside look at the power-generation, -regulation, and -delivery system for the Phoenix Mars lander. Read More...

LED lighting teardowns: Five lighting designs that illuminate the future of lighting

Early SSL products are making their way onto store shelves and into inventory. These products can indicate what direction SSL design will take, at least in its early stages. Read More...

Tear-down: inside a 7W LED light bulb

A 5000K version of a 7W LED bulb served as the sacrificial lamb to see what's inside. Read More...

LED bulbs reveal different design approaches

A peek into the Philips LED bulb’s electronics and the 6W, dimmable Pharox 300 contrasts two approaches in how a bulb handles the protection of the LED-power-control electronics. Read More...

>> SEE ALL

Parallel Operation Minimizes Temperature Rise in Synchronous 4-Switch Buck-Boost Converters

A single synchronous buck-boost DC/DC converter can deliver high power due to its synchronous switching topology, but eventually the switching and/or conduction losses at higher power can overwhelm a single converter with excessive board heating. Although heat can be mitigated with bulked up heat sinks, additional external gate drivers, and/or forced airflow, it may be better to simply tie together two or more converters in parallel to spread the load. This is easy to do with the LT3790 4-switch synchronous buck-boost DC/DC converter. Read More...

Reducing cost & complexity of LCD LED backlights with single-IC, single-inductor multi-string LED driver architectures

In his fourth installment we'll look a single-IC, single-inductor multi-string LED driver architectures which provide great savings in both solution cost and PCB real estate. For this tutorial, we'll use the LT3598 which can drive up to six strings of ten LEDs at up to 30mA per string and a built-in power switch. Read More...

Powering LED Lighting & Other Illumination Devices: Part 3

This third installment of a multi-part series on design issues in LED lighting explores the capabilities of the LT3799, a high-power factor, self-isolated, TRIAC-compatible LED driver. It includes several practical examples of how these properties can be used to solve common design issues for LED applications in a simple, cost-effective manner. Read More...

Powering LED Lighting & Other Illumination Devices: Part 2 (Updated)

This second installment of a multi-part series includes several practical examples based on the LT3791 is a 4-switch synchronous buck-boost DC/DC converter that regulates both constant-current and constant voltage at up to 98.5% efficiency with a single inductor. Read More...

Powering LED Lighting & Other Illumination Devices - Part 1

This first installment of a multi-part series on design issues in LED lighting presents several solutions to the challenges of driving the series strings of HBLEDs frequently used in DLP projectors, stage lighting, automotive lighting and other applications traditionally served by high intensity bulbs. It includes several practical examples based on the LT3763, a 60V synchronous, step-down DC/DC controller designed to accurately regulate LED current at up to 20A with fast PWM dimming. Read More...

Tips and tricks for driving WS2811 LED strips - Part 1: Taming the wily WS2811

Here's a summary of some of the key design issues and a few resources to help shorten your LED strips learning curve. Read More...

A simple method for determining the optimal operating point of an LED

Field applications engineer Donald Schelle shares a simple method for optimizing the performance of LEDs. He shows how to use the information on an LED's data sheet to perform the necessary trade-offs to produce the best mix of cost, efficacy, and weight for your particular LED application. Read More...

An insider's guide to designing near-eye displays

Carlos Lopez and Dan Morgan from Texas Instruments' DLP Pico Products group take an in-depth look at some of the top challenges for designing a compelling see-through near eye display solution that “seamlessly” blends the digital world with the physical world. Read More...

LEDs for liquid crystal display (LCD) backlighting – Part 2

In Part 1, the author described the types and structures of LED LCD backlight units and their relative advantages. This installment concluded with a summary of market requirements for BLUs and a history of how they've driven their development. The second and final installment of this book excerpt begins with a close look at recent market trends and technological developments and concludes with the key points in the optical design of LED backlights. Read More...

LEDs for liquid crystal display (LCD) backlighting – Part 1

The first installment of this two-part series introduces the types and structures of LED LCD backlight units. This is followed by a dive into the technological developments and market trends which are driving the evolution of LED displays. Read More...

LED-based sensors for wearable fitness tracking products

The surge in bio-sensing armbands, smartwatches, smartphones, and other fitness-oriented wearable products that employ optical sensing technologies would not have been possible without the dramatic reductions in cost and power brought by LEDs. Read More...

The changing role of LEDs in automotive lighting - Part 2

Part 2 of an excerpt from the book "Nitride semiconductor light-emitting diodes (LEDs)" looks at the key differences between LED and filament sources in terms of visual responses, as well as the energy and environmental implications for LEDs in automobiles. Read More...

The changing role of LEDs in automotive lighting applications - Part 1

Part 1 of an excerpt from the book "Nitride semiconductor light-emitting diodes (LEDs)". This installment explores the photometric requirements of vehicular lighting illumination and signaling systems and how LED light sources are being used to create innovative solutions to meet them. Read More...

Designing building & installing a homemade 12VDC LED lighting system

With the arrival of the LED lighting revolution and efficient DC-DC converters, an engineer revisits his cabin’s battery-powered lighting system. Read More...

OLED microdisplays made simple

At this week's SID Display Week conference taking place in San Diego, Dr. Alexander Zakhidov presented COMEDD’s latest development for the manufacture of high resolution OLED microdisplays. Read More...

LED Drivers—Match architectures with applications

Several basic architectural options available to designers. By understanding and comparing the strengths and weaknesses of each, it is possible to select the best driver solution for the application at hand. Read More...

>> SEE ALL

LED Lady, Rumblings of China LED industry shakeout , Metal-free OLEDs on the horizon

In this week's Semi-Coherent Emissions we welcome Lindsay Wood, aka "The LED Lady" as this section's first V-blogger. Also as the latest Chinese LED manufacturer to close its doors signals some "interesting times" ahead. Read More...

The Hat at Maker Faire - Day 1

The Hat's had a busy time at the first day of the Maker Faire. Between watching high-powered kiddie car races, performing for visitors, and helping build mini-Smart Hats, there was barely enough time to get out of the booth to see a few sights. And wondrous sights they were indeed! Read More...

Greetings from Maker Faire 2015

One half embedded development platform, one half photonic fashion statement, and 100% attitude, Editor Lee Goldberg's "Smart Hat" is on its first solo assignment: report on some of the DIY activities at the Bay Area Maker Faire. Read More...

Celebrate DIY Victorian high-tech at the Steampunk World's Fair

It's time to dust off your goggles, charge up your ray gun and set your airship's course for the Steampunk World's Fair. Held May 15-17 in Piscataway, New Jersey, the fair is a Mecca for DIY-ists who take a somewhat unique approach to technology, fashion, and alternate history. Read More...

Smart vs. Fart Lighting, wood-powered LEDs and levitating lightbulbs?

Lightfair is full of surprises, including a heat-powered LED lantern and a Smart Lighting System with a sense of smell. And has "Smart Lighting" become the lamest buzzword of the year? Read More...

Meet me at Lightfair - Meet my Smart Hat at Maker Faire!

If you are attending Lightfair on May 5th or 6th, please join me for coffee, industry gossip, and a healthy dose of geek fellowship at EDN's Reader/Editor Meet-Up. Normally, I'd be very easy to spot because I'd be wearing my Smart Hat, but this time I'll be a bit harder to pick out of the crowd. That's because The Hat is on its way to the Maker Faire. Read More...

LEDs battle ebola and climate change while boosting the economy

This week's Semi-Coherent Emissions top story: The LED lighting industry's performance provides compelling evidence that strong economic growth and high environmental quality aren't mutually-exclusive. Read More...

Air Force reveals its new aircraft cloaking system uses dark-emitting diodes (DEDs)

Star Trek has finally met its match in real life with the U. S. Air Force’s revelation of a new stealth technology based on dark-emitting diodes (DEDs). Read More...

IoT Standards in Flux, LEDitor meetup at Lightfair and Thunderstruck Lumen Lust

Philips seminar on Semantic Lighting, the upcoming LightFair in NY City, IoT standards wars and a bespoke LED-lit interactive thundercloud top this weeks semi-coherent sightings in the solid-state ligthing universe. Read More...

Get your geek on for Pi Day - 3-14-15

Take a look at how the nation's geekiest town celebrates Pi Day and use the links we've provided to help you locate the irrational revelries in your home town. Read More...

Educating the Smart Bulb

I'm convinced that smart bulbs and smart luminaires may eventually become a viable alternative to traditional lighting control systems, but you'd never know it from what's being sold today. Has anybody thought deeply about the useful things which smart lighting could be good at doing? Read More...

Educating Smart bulbs, LEDs that eavesdrop, More Lumen Lust, and meet the LEDitor at 2 great LED events in NY.

This week's sightings from the photonic sector include IMS' networked smart daylighting manager IC, a smart music player which could teach smart bulbs a thing or two, and a chilling video about how LED bulbs might be used to listen in on your conversations. Read More...

Is 2015 "The Year of the LED"? - Printed optics combat light pollution - Meet your LEDitor at LEDuction 9

Is 2015 "The Year of the LED"? - Printed optics combat light pollution - Meet your LEDitor at LEDuction 9. All this and more in in this week's Semi-Coherent Emissions blog! Read More...

LED Wars, Road Warriors, and Smart Cities in this week's Semi-Coherent Emissions

This week's Semi-Coherent Emissions blog includes news on Cree's lawsuits against competitors, a definitive text on roadway lighting with LEDs, and a consumer's guide to solid-state lighting. Read More...

Let's get LEDucated!

Join me March 5&6 in NY City at the LEDucation conference! It lives up to its name by providing both a chance to kick the tires on the latest LED lighting products and to attend a program of highly-informative panels, seminars and workshops led by some of the industry's top authorities. Read More...

Closing the green gap, magnetic lumen lust and hooking kids on LED tech

In this week's Semi-Coherent Emissions blog: Osram reveals 2 prototype green LEDs with record-breaking efficacy, a discussion on the search for anything that might ignite kids' interest in lighting technology and the latest addition to Lee's utility pouch. Read More...

Foraged crabapple jelly – a delicious DIY holiday a gift

Crabapple jelly is a perfect "gateway drug" to get you hooked on home preserves because it's one of the easiest of jellies to make and, if you find the right fruit, one of the most delicious. Although seldom found in stores, there's a good chance you can forage your own crabapples from trees growing within a short drive of your house. Read More...

LED-lit urban farms aim to transform blighted cities with jobs, fresh food

A group of high-tech urban pioneers is using LEDs to power an indoor vertical farming system that will create good paying jobs and delicious pesticide-free greens. Read More...

LEDs brighten the holidays, launch fashion trend, refute climate skeptics

This week's top stories include: "LED lighting officially declared a No-Brainer for most Businesses", a look at how Corning's new light diffusing fiber may find its way into clothing, and a new Li-Fi system which lets objects speak for themselves. Read More...

Semi-Coherent Emissions: Ghostly LED-lit skiers haunt Alaska's slopes

LED-encrusted suits bring night in the Alaskan wilderness alive in hauntingly-beautiful ski film, the upcoming Bluetooth/ZigBee war, Mercedes' 84-LED headlamps paint the road with smart light. Read More...

Semi-Coherent Emissions: Are smart bulbs gateways for cyber-terrorists?

This week, LEDitor-in-Chief Lee Goldberg ponders oval video pixels, takes a quick peek inside Cree's new Flow4 LED bulb, shares a colleague's insightful critique of the so-called rebound effect and wonders whether cyber-terrorists can rally weaponize smart bulbs. Read More...

Semi-Coherent Emissions: October 15, 2014

Can LEDs conquer the Monday morning blues? What's with those "AC LEDs" that Samsung's recently Announced? And What's GE hiding inside its GE Link Smartbulb? You'll find the answers to these pressing questions a second opinion on the so-called "rebound Effect" and a toast to the Nobel Laureates who invented the blue LED In this week's Semi-Coherent blog. Read More...

First graphene-based flexible display is unveiled

For the first time graphene has been used in a transistor-based flexible device which promises to open opportunities to enabling fully wearable and flexible devices. Read More...

LED conspiracy theory

AllLED Lighting’s recent discussion about a article posted June 23 on LED Insider about Philips Lumileds’ admonition to the industry to explore strategies for adding value and differentiating their products raises several interesting questions – none of which I’ve got an answer for. Read More...

Semi-Coherent Emissions: NFC makes Bluetooth smarter, LED-mania makes crowdfunding dumber, Philips denies patent trolling

Lee's latest non-random sampling of the premier products, trending technologies, gossip and goings-on within the solid-state lighting universe. Read More...

Comparing handheld spectrometers - what matters to SSL pros (like you)

"Whether you’re designing LED lights or using them, a handheld spectrometer is as essential to your trade as a pocket knife is to a boy/girl scout on a camp-out" says Dennis McCarthy, LED lighting technologist and EDN columnist. "Whatever your application, a spectrometer is a great antidote for the growing levels of snake oil in the LED industry. The cold, hard data these little wonders put in your hand are invaluable for separating the truth from installer’s or manufacturers’ claims.” Join Dennis for an insiders’ look at one of the tools of his trade. To help you decide which unit would best suit your needs, Dennis shares his thoughts on the three units he’s had the good fortune to play with personally during his adventures in the realm of lighting. Read More...

Semi-coherent emissions: 30 rules of lighting, UVLED 3D printer & lumen lust

The latest non-random sampling of premier products, trending technologies, gossip and goings-on within the solid-state lighting universe. Compiled, Curated and Commented by Lee H. Goldberg – Managing Editor, EDN’s LED Design Center. Read More...

Hackspotter: World's most dangerous LED display caught at Maker Faire

Stay clear of the whirling sphere please, this is not a toy! Weighing in at over 350 lbs, the Orbital Rendersphere is a whirling LED array which uses the persistence of vision effect to paint 360 degree images in thin air. Read More...

IoT-ready Smart Lighting manager ICs feature integrated daylighting, spectral management and multi-sensor support.

Ams's new Smart lighting manager ICs support network-commanded dimming, daylighting and other basic smart lighting functions as well as an autonomous mode which only relies on a local or remote host for configuration and exception handling. Unlike most of their counterparts, they have highly-accurate built-in light sensors which enable precise daylighting, lumen maintenance, and in the case of the AS7221, color tuning. In addition, the same sub-$10 solution that drives the lighting system can also serve as a low-cost platform for many other Smart Building services. Read More...

LEDs tap indoor location technology for social shopping

The next generation of LED lighting fixtures that communicate with shoppers' smart devices while in-store, enabling retailers to provide new location-based services have been revealed by GE Lighting and ByteLight. Read More...

Parallel Operation Minimizes Temperature Rise in Synchronous 4-Switch Buck-Boost Converters

A single synchronous buck-boost DC/DC converter can deliver high power due to its synchronous switching topology, but eventually the switching and/or conduction losses at higher power can overwhelm a single converter with excessive board heating. Although heat can be mitigated with bulked up heat sinks, additional external gate drivers, and/or forced airflow, it may be better to simply tie together two or more converters in parallel to spread the load. This is easy to do with the LT3790 4-switch synchronous buck-boost DC/DC converter. Read More...

Reducing cost & complexity of LCD LED backlights with single-IC, single-inductor multi-string LED driver architectures

In his fourth installment we'll look a single-IC, single-inductor multi-string LED driver architectures which provide great savings in both solution cost and PCB real estate. For this tutorial, we'll use the LT3598 which can drive up to six strings of ten LEDs at up to 30mA per string and a built-in power switch. Read More...

EDN field-tests the ultimate LED party lights

BlissLights makes some seriously cool toys. When I gave a brief shout-out to them in a recent Semi-coherent Emissions blog I knew I had to get my hands on a couple of these grown-up party bulbs. Happily, BlissLights cheerfully loaned me a few of their photonic toys so I could subject them to a little real-world testing at my St. Patrick's Day party. Read More...

LED light guides deliver affordable OLED-like performance

Sleek, stylish and seductively luminous, OLED panels' silky, eerily-even glow has made them a favorite for fashion-forward lighting designers, even though they cost more, were shorter lived, and more easily damaged. This may change however, as Global Lighting Technologies' (GLT) introduces a growing number of products based on its edge-lit LED-based light guide technology. Read More...

Powering LED Lighting & Other Illumination Devices: Part 3

This third installment of a multi-part series on design issues in LED lighting explores the capabilities of the LT3799, a high-power factor, self-isolated, TRIAC-compatible LED driver. It includes several practical examples of how these properties can be used to solve common design issues for LED applications in a simple, cost-effective manner. Read More...

Powering LED Lighting & Other Illumination Devices: Part 2 (Updated)

This second installment of a multi-part series includes several practical examples based on the LT3791 is a 4-switch synchronous buck-boost DC/DC converter that regulates both constant-current and constant voltage at up to 98.5% efficiency with a single inductor. Read More...

Zener-enhanced Dark Emitting Diodes (ZeDEDs) deliver 10X more Dark per Watt

YoYo Dyne Systems' new family of Zener-enhanced dark-emitting diodes (ZeDEDs) features a novel junction structure and an integrated light sink to achieve a 10X boost in performance over equivalent-sized conventional darkness emitters. Read More...

Wireless-enabled LED lighting drivers reduce product integration and deployment costs

By embracing Daintree's philosophy of developing control systems that support open standards, LG is also encouraging development of innovative and affordable products. Read More...

Step-down driver furnishes up to 40 A of LED current

The LT3744 synchronous step-down DC/DC converter from Linear Technology delivers constant current to drive high-current LEDs, while its 3.3-V to 36-V input voltage range accommodates a wide variety of applications, including industrial, DLP (digital light processing) projection, and architectural lighting. Read More...

15W TRIAC-dimmable, Energy Star-compliant LED drivers work smoothly with nearly any dimmer

Although Phihong USA's new series of 15W TRIAC-dimmable constant current LED drivers sacrifices some efficiency and power quality performance for the sake of compatibility and cost, the drivers are still worth considering for many applications. Read More...

Powering LED Lighting & Other Illumination Devices - Part 1

This first installment of a multi-part series on design issues in LED lighting presents several solutions to the challenges of driving the series strings of HBLEDs frequently used in DLP projectors, stage lighting, automotive lighting and other applications traditionally served by high intensity bulbs. It includes several practical examples based on the LT3763, a 60V synchronous, step-down DC/DC controller designed to accurately regulate LED current at up to 20A with fast PWM dimming. Read More...

Tips and tricks for driving WS2811 LED strips - Part 1: Taming the wily WS2811

Here's a summary of some of the key design issues and a few resources to help shorten your LED strips learning curve. Read More...

Dual-protocol wireless control modules enable smart, networked LED drivers, luminaires, bulbs, and wall plugs

The first two implementations of the dual-protocol platform are a multi-mode (0-10V or DALI) Bluetooth lighting controller and a Class 2 embedded Bluetooth 4.0 module. They can be integrated into lighting fixtures, LED drivers, and LED smart bulbs. Both the Bluetooth controller and lighting module are programmed to automatically form a self-healing and self-organizing wireless mesh network with any other Casambi-enabled devices within "earshot" of it. Each device can also be paired to a Bluetooth Smart Ready smartphone or tablet, enabling any fixture within the mesh to be controlled from any other point without the need for an external gateway module. Read More...

LED lighting aspects in parking structures

Many people do not realize the effect that lighting can have on the human experience. Read More...

A simple method for determining the optimal operating point of an LED

Field applications engineer Donald Schelle shares a simple method for optimizing the performance of LEDs. He shows how to use the information on an LED's data sheet to perform the necessary trade-offs to produce the best mix of cost, efficacy, and weight for your particular LED application. Read More...

Networked, color-tunable troffer makes high-quality lighting affordable, easy to install

Although I have a few unresolved issues regarding its SmartCast wireless control technology, I'm posting this review because Cree's new Troffer is one of the first commodity-level products I've seen which makes a respectable attempt at realizing solid-state lighting technology's full potential instead of simply being a more efficient light bulb. Read More...

Wi-Fi equipped 32-bit Arduino board streamlines cloud-powered embedded app development

Digilent's chipKIT WiFire board is an awesome little beastie. Powered by Microchip's powerful 32-bit 200 MHz MCU, the Wi-Fi equipped Arduino-compatible platform has been paired with Imagination Technologies' Flow Cloud service development tools in an effort to make creating cloud-powered embedded applications practical for the average developer. Read More...

An insider's guide to designing near-eye displays

Carlos Lopez and Dan Morgan from Texas Instruments' DLP Pico Products group take an in-depth look at some of the top challenges for designing a compelling see-through near eye display solution that “seamlessly” blends the digital world with the physical world. Read More...

MD&M West steps up its game through Allied Electronics at Center Stage Gadget Freak event

This year, at MD&M West there will be a Gadget Freak Workshop presented by Allied Electronics in the Center Stage area of the Anaheim Convention Center. Read More...

Mid- & Hi-Power LED drivers feature on-chip PFC, thermal/electrical protection

On Semiconductors' new series of power factor corrected (PFC) offline AC-DC LED drivers bring the same high levels of integration and application-specific features usually found only in lower-powered drivers to mid- and high-power SSL applications. Read More...

LEDs for liquid crystal display (LCD) backlighting – Part 2

In Part 1, the author described the types and structures of LED LCD backlight units and their relative advantages. This installment concluded with a summary of market requirements for BLUs and a history of how they've driven their development. The second and final installment of this book excerpt begins with a close look at recent market trends and technological developments and concludes with the key points in the optical design of LED backlights. Read More...

Compact high-output LED module enables innovative designs for theatrical-type lighting equipment

Osram's Ostar Stage multi-element LED's high output and compact form factor of the 4-LED (RGBW) module which could be just what designers need to create a new generation of affordable, efficient, lighting products for theatrical, exhibition and architectural applications. Read More...

ZigBee 3.0 radio chips and modules can add Smart Home/IoT capabilities to lighting applications

GreenPeak Technologies' GP691 communication controller chip and GPM6000 integrated Modules provide a much-needed solution for implementing ZigBee 3.0, Thread, and other advanced wireless protocols. Read More...

LEDs for liquid crystal display (LCD) backlighting – Part 1

The first installment of this two-part series introduces the types and structures of LED LCD backlight units. This is followed by a dive into the technological developments and market trends which are driving the evolution of LED displays. Read More...

Intelligent four-channel LED driver offers design flexibility

Code Mercenaries has introduced a 4-channel, intelligent, programmable LED driver which has I2C, DMX512, and DALI interfaces. Read More...

Two-string HB automotive LED driver provides 10000:1 dimming ratio

For use in automotive display backlights, automotive lighting applications and LCD backlights, Maxim has posted detail of the MAX16838B which it says is the only-available 2-String HB LED driver providing 10000:1 dimming ratio. Read More...

Triple LED controllers for rear lights

The IC family E522.80/81/82/83 from Elmos AG is an LED controller device, designed for applications like automotive rear lights. The devices offer three channels each, with a maximum current of 140 mA. Read More...

LED-based sensors for wearable fitness tracking products

The surge in bio-sensing armbands, smartwatches, smartphones, and other fitness-oriented wearable products that employ optical sensing technologies would not have been possible without the dramatic reductions in cost and power brought by LEDs. Read More...

Arduino LED controller shield makes complex RGB LED lighting apps a snap

The Arduino-compatible lighting RGB LED lighting shield reviewed here was designed to give designers a low-cost easy-to-use open-source platform for fast prototyping and inexpensive evaluation of multiple LED light engines. Read More...

The White House goes digital for the holidays

The team in the Office of Digital Strategy and other staffers and volunteers at 1600 Pennsylvania Ave are mixing things up this year, working with several innovative companies to incorporate elements of modern technology into the traditional holiday decorations. Read More...

Cloud-based Smart Building system enables genius-level Smart Lighting

Daintree Networks' subscription-based cloud application provides a full suite of building and energy management services including genius-level Smart Lighting capabilities. Read More...

Wearables make hardware the new software

As wearables ranging from the likes of Apple to open source expand, hardware is the new software with disruptive intellectual property offering up the potential for explosive designs and market growth. Read More...

Smart light's bright future

After changing the way we think about light, human-centric lighting is poised to change the places where we work, live, and play. Read More...

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