LEDs

EDN Staff

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.

Reference design demos no-neutral BLE wall switch

Power Integrations’ DER-622 document illustrates a wireless wall switch that does not require a neutral return wire to power the unit. Read More...

Are “beam array” headlights in automotive’s future?

Everyone complains about headlights, but now, someone’s doing something about it. Can smart beam arrays better illuminate the road while causing less glare for other drivers? Read More...

NASA growing food in space: An amazing technological feat

When future astronaut crews begin living and working at more distant destinations in space, they will need to take a little of the Earth with them in order to breathe and eat their vegetables. Read More...

What’s in store for optical biosensors? Part 2

This article looks at common noise and error sources affecting optical sensing, the current capabilities of wearable biosensors, and the future direction of optical biosensing applications. Read More...

Power Tips #81: Make sure your optocoupler is properly biased

When you are designing an isolated feedback network, you must consider the tolerance of the optocoupler and all other components that determine the large signal gain. Read More...

Designing LEDs for hazardous environments

Discussing LED lighting design for hazardous and electrically challenging environments. Read More...

What’s in store for optical biosensors? Part 1

Optical sensors represent the most common type of biosensor. This two-part series provides a technical background on how optical techniques are used for bioanalytical applications. Read More...

Powerful LEDs reach 200 lm/W

Samsung has introduced the LM101B and LH231B white LEDs in “chip-scale” packaging, at 1W & 5W power levels. Read More...

They're still selling incandescent flashlights?

The typical consumer flashlight now has an ANSI/NEMA standard for defining performance across various parameters, so you can compare units with different light sources. Read More...

LED lighting design considerations for smart cities

Whether for Smart Cities or not, don’t miss any details when designing LED lighting systems and associated sensor hubs. Read More...

Designing fast, isolated microamp current sources: Part 3

Need to test photodiode receivers or provide isolated megahertz current signals? Here’s Part 3 of our in-depth design guide. Read More...

Whipping a cheap LED PSU into usable shape

You get what you pay for, and sometimes not even that, but even a cheap Chinese PSU can be improved with some judicious tinkering. Read More...

LED lighting system reliability: Ensuring a robust design

Manufacturers and standards bodies are getting serious about LED lighting reliability. Get your feet wet here, and stay tuned as we continue to explore this topic further. Read More...

Man’s endeavor to live beyond planet Earth

NASA Earth-independent activities are building on what they learn on the International Space Station and in deep space to enable human missions to the Martian surface. Read More...

Designing fast, isolated microamp current sources: Part 2

Need to test photodiode receivers or provide isolated megahertz current signals? Here’s an in-depth design guide. Read More...

Connected lighting may be the IoT killer app

Connected lighting is a huge potential market that might energize the IoT. Read More...

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Multi-brightness LED controller draws zero off-current

This quaint design offers up a battery-operated LED lantern with multiple brightness levels. Read More...

LED strings driven by current source/mirror

This unusual dual-output current source can, for example, drive LED strings at any desired current ratio. Read More...

LED current regulator has low dropout

Meet an interesting addition to the field of LED current regulators. Read More...

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...

An LED's intrinsic capacitance works in a 650-mV LRC circuit

The LED and a discrete inductor form an LC tank circuit. Read More...

LEDs indicate sound level

Build a battery-operated portable meter to measure sound-pressure levels. Read More...

Driver circuit lights architectural and interior LEDs

Hold the current constant and within tolerance. Read More...

LED-current limiter accepts ac or dc

Prevent excessive current from overdriving your LEDs. Read More...

Protect power-LED strings from overcurrent

Add diodes and a transistor to a current mirror to prevent LED damage. Read More...

Efficient LED power supply has battery backup

Power three to six LEDs from an ac- or dc-power source and charge a backup battery. Read More...

High-power LED drivers require no external switches

Suiting a variety of applications, these circuits transform a switching regulator into a current source for driving power LEDs. Read More...

Line-powered driver lights up high-power LEDs

LED array reduces power and maintenance expenses. Read More...

Linear and switcher LED supplies combine, overcome disadvantages of each topology

Linear and switcher LED supplies combine to overcome disadvantages of each topology. Read More...

Readers' Choice: Vote for your favorite Design Ideas

Community driven, Design Ideas have always resonated deeply with EDN’s audience, with their inspired, hands-on, practical, and useful circuit-design contributions. Vote for the ‘best of the best’ here. Read More...

Adjust power-efficient LED switch to any light intensity

Drawing only microamps (other than load current), this circuit switches in accordance with ambient light levels. Read More...

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LED driver offers dual dimming modes

A single-stage LED driver-converter with an integrated 2 A, 600 V MOSFET, Diodes’ AL1673 allows both PWM and analog dimming. Read More...

Horticulture LEDs extend color choices

Lumileds has added three new colors to its Luxeon SunPlus 35 line of LEDs, enabling wavelength tuning in greenhouses and vertical farming. Read More...

Chip-on-board LEDs deliver high lumen output

Optimized for high drive currents, Cree’s XLamp CMA LED arrays provide more than 2X the lumen density of its standard-density CXA2 LEDs. Read More...

Powerful LEDs reach 200 lm/W

Samsung has introduced the LM101B and LH231B white LEDs in “chip-scale” packaging, at 1W & 5W power levels. Read More...

Mini LED fits mobile devices

Leveraging a chip-scale package for even illumination, the Ceramos C compact LED from Osram is just 1.4×1.4×0.21 mm. Read More...

Multichip LED improves camera flash

The latest addition to Osram’s Oslux family of LEDs, the S2.1 comprises two LED chips and a lens integrated into a single compact module. Read More...

High-power LED suits outdoor use

With the introduction of the 5 W LH351C, Samsung has broadened its lineup of high-power LEDs for use in both indoor and outdoor applications. Read More...

LED lends color to decorative lighting

Expanding Cree’s family of architectural-lighting class LEDs is the CLQ6A, an individually addressable RGBW (red, green, blue, and white) LED. Read More...

LED module packs big candela punch

Based on Plessey’s Stellar beam-forming optics, the Orion series of slim LED modules boasts a center-beam intensity of up to 7200 candelas. Read More...

LED driver packs PWM generator

Linear Technology’s LT3932 step-down DC/DC converter offers fixed-frequency, peak current control and PWM dimming for a string of LEDs. Read More...

Single-die LED delivers 1700 lumens

Housed in a chip-scale package, Lumileds’ Luxeon V LED produces more than 1700 lumens at 5700K, while occupying a 4×4-mm footprint. Read More...

IC drives long LED strings

Microchip’s CL88020 sequential linear LED driver for offline lighting drives a long string of LEDs directly from a 120 VAC line input. Read More...

LED controller assists auto lighting

A synchronous buck LED controller, Maxim’s MAX20078 provides fast response time and low EMI for automotive exterior lighting. Read More...

Software eases LED driver programming

Thomas Research Products offers the SelectSYNC Universal Configurator tool for programming the company’s LED drivers on the production line. Read More...

IC performs lumen maintenance

The AS7220 Smart Lighting Manager from ams uses closed-loop sensing to maintain accurate CCT and lumen output of LED lamps. Read More...

Phase-cut LED drivers pack a power punch

At 24 W, Seoul Semiconductor’s NanoDriver series of phase-cut LED drivers delivers 10 times the power density of conventional LED drivers. Read More...

LEDs offer high brightness from small packages

Super red, red, amber, and yellow ultrabright LEDs in the VLDx1535 series from Vishay come in surface-mount packages with dome lenses. Read More...

Keysight adds 50/70/100 MHz oscilloscopes for educators, small labs

The InfiniiVision 1000 X-Series brings higher-end features within budgets of educators, small labs, and even individuals. Read More...

Infrared LED aids iris scanners

Used for iris recognition, OSRAM’s SFH 4787S infrared LED operates at 810 nm to permit high-contrast images for all eye colors. Read More...

LED grow lights replace sodium lamps

Hyperion horticultural LED grow lights from Plessey provide supplementary lighting in greenhouses, while achieving a 40% energy savings. Read More...

RGB LED improves contrast ratio

According to Cree, the C1010 surface-mount RGB LED achieves a 40% better contrast ratio and a longer lifetime than competing LEDs. Read More...

Rohm shrinks reflector LED size

At just 1.8×1.6 mm, the MSL0402RGBU reflector-type, three-color LED from Rohm enables high-density matrices in gaming and wearable devices. Read More...

LED drivers pack wireless controls

WorkHorse LED Extreme drivers from Fulham are programmable constant-current drivers built to withstand harsh environments. Read More...

CFL-replacement LED achieves DLC 4.0 listing

Lunera’s 26-W, 4-pin G24q LED lamp delivers a lumen output that is nearly 50% greater than the previous generation. Read More...

UV LEDs double power, shrink package

Luxeon UV U1 ultraviolet LEDs from Lumileds deliver twice the radiant power of previous-generation devices at 380 nm to 390 nm. Read More...

LED produces over 2500 lumens

Cree’s XLamp XHP50.2 LED delivers up to 7% more lumens and 10% higher LPW (lumens per watt) than the first-generation XHP50 LED. Read More...

Lighting manager offers spectral tuning

A smart-lighting manager, the AS7221 from ams is a network-enabled device that provides CCT tuning for white LED smart lighting. Read More...

LED driver handles 100 W

Thomas Research Products’ LED100WPS1-24 constant-voltage driver can be used in both indoor and outdoor commercial and industrial applications. Read More...

Broadband IR LED enables food analysis

Osram’s SFH4735 LED emits broadband IR light over a wavelength range of 650 nm to 1050 nm to serve as a light source for near-IR spectroscopy. Read More...

Multichip LEDs suit entry-level ADB headlights

Osram’s Oslon Black Flat S series of surface-mount LEDs comprises configurations containing up to five individually controlled chips. Read More...

LED driver furnishes up to 40 W

A hysteresis-mode DC/DC step-down converter, the AL8860 from Diodes Inc. drives single or multiple series-connected LEDs. Read More...

LED driver fits small screens

A current-mode boost LED driver, Diodes’ AL3050 packs a 30-V MOSFET and Schottky diode to enable it to drive up to eight LEDs in series. Read More...

Control device simplifies LED dimming

Inspired LED’s Triac Analyzer allows low-voltage LED systems to be controlled using almost any standard triac wall dimmer. Read More...

Lighting system brightens enclosures

Rittal offers the SZ 2500 series of LED system lights to illuminate every corner of an industrial enclosure, from ceiling to floor. Read More...

Multi-die LEDs simplify optical design

Luxeon 5050 LEDs from Lumileds are housed in a multi-die package with a round light emitting surface that is just 4.6 mm. Read More...

Step-up converter drives LED strings

A monolithic synchronous step-up DC/DC converter, the LT3922 from Linear Technology, packs 40-V, 2-A power switches and a PWM generator. Read More...

Side-view LEDs enhance gaming experience

Cree’s QLS6A and QLS6B bright side-view LEDs deliver up to 66% higher luminous intensity than other side-view LEDs. Read More...

LED floodlights meet diverse market needs

Eaton has expanded its Lumark Night Falcon LED floodlight series with large and small models to replace HID lamps rated from 70 W to 1000 W. Read More...

LEDs brighten food display cases

Lumileds now offers its Luxeon Stylist Series COB LEDs with FreshFocus technology to showcase breads and pastries in an appetizing light. Read More...

Rugged indicators employ recessed LEDs

Front panel-mount diffused LED indicators in the L65 series from VCC snap into a 0.315-in. (8.0-mm) panel hole without additional hardware. Read More...

ICs drive up to 192 LEDs

ISSI’s IS31FL3733, IS31FL3736, and IS31FL3737 driver ICs handle LED matrices comprising 192, 96, and 144 LEDs, respectively. Read More...

High-power LEDs lower system costs

Optimized to simplify directional and semi-directional LED system designs, the XLamp MHB-B series from Cree delivers up to 931 lumens at 85°C. Read More...

HID LEDs deliver up to 20,000 lumens

Lunera’s third-generation of HID LED lamps includes one of the first line-driven 20,000-lumen HID LEDs to replace 400-W MH and HPS lamps. Read More...

Mid-power UV LED operates at 365 nm

A ceramic-based UV LED, the VLMU1610-365-135 from Vishay provides typical radiant power of 18 mW at 20 mA and 50 mW at 60 mA. Read More...

Energy-efficient LED lamp replaces HID lamps

Lunera’s HID LED 360 lamp for architectural post-top fixtures replaces MH and HPS HID lamps, while lowering energy and maintenance costs. Read More...

Display driver shield speeds prototyping

The MAXREFDES99# Arduino and mbed-compatible reference design from Maxim enables the creation of 16×16 LED arrays for signage applications. Read More...

LED driver suits buck topologies

LYTSwitch-1 from Power Integrations is a family of single-stage, nonisolated buck LED drivers that ensures high power factor and low THD. Read More...

Backlighting kit offers trimmable panels

Lumitex offers the Cut-2-Size backlighting kit for easy prototyping of membrane switches, keypads, overlays, LCDs, and other graphic displays. Read More...

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Teardown: What killed this LED bulb?

A failed 60W-equivalent A19 LED light bulb provided an intriguing teardown opportunity, but what caused the failure? Read More...

Teardown: LED touch controllers & PSU

Look inside some low-cost LED touch controllers. Read More...

Teardown: Motion-sensing LED lighting

An AC power source and motion-sensor activation combine to create some notable design differences between this LED light and its battery-powered, touch-operated Enbrighten sibling. Read More...

Teardown: Cool LED lighting

How does Jasco's Enbrighten battery-powered guide light deliver on its coverage and temperature claims? Find out in this teardown. Read More...

Teardown: LED light shrinks size, cost with non-isolated driver

What has changed in LED bulb design to allow the steep drop in prices that is happening? Tearing apart a LED bulb provides a look at some of the design trends in LED lighting. Read More...

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

See inside this fully dimmable Samsung bulb that puts out 550 lumens of a nice warm white (3000K), consumes 10W, and boasts a five-year warranty. 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...

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...

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...

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...

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Lightfair 2017: Making lighting design simple, smart, and beautiful

This year’s Lightfair was again focused on IoT and connected lighting with proof of IoT’s benefits strongly represented, along with innovative LED power ICs and artistic lighting displays. Read More...

Secrets for designing with flashing LEDs

Having multiple LEDs flashing at different rates is not necessarily difficult. Read More...

Measurement basics in LED thermal management

It takes more than the ability to read a datasheet to figure out the thermal aspects necessary for your LED design—here’s some help. Read More...

The DB-100 controller: A breakthrough in simplifying LED control

The DB-100 controller will simplify high-CRI, dimmable, variable-color-temperature LED control. Read More...

LEDs will inherit the world

In 60 years, all lighting functions will be handled by LEDs, and it will be a substitute for Wi-Fi. Read More...

What you don’t know about LED light intensity curves for grow light apps

We know a lot about how light intensity curves work—but you may not know about the concept described in this article. Read More...

Basic flashlamp illumination circuitry for cellular telephones and cameras

The LT1618 is an ideal IC for providing constant current to Lumileds white LEDs from a variety of power sources. Read More...

Monolithic converter drives high-power LEDs

LED drivers must regulate a constant LED current, regardless of input and output voltages. Now a single switching regulator with the ability to be configured in a variety of topologies for high power constant LED current is available. Read More...

LEDs go everywhere

It has been a long time coming, but the cost structures normally associated with LED equivalents have dropped dramatically over the past 5 years or so, and the future is bright for LED bulbs. Read More...

LED lighting: More intelligent, more beautiful, more affordable

The LED industry's products will become more efficient, reliable, and, one can hope, interoperable in the near future. But underlying all these advances will be the relentless pressure to deliver LEDs at lower price points. Read More...

Addressing design issues when working with UVC LEDs

With careful consideration, UVC LEDs can decrease footprint and power consumption, improving cost of ownership for the end user. Read More...

Wide input range 1A LED driver powers high brightness LEDs with automotive and 12VAC supplies

The LT3474 LED driver allows today’s ultrabright LEDs to far exceed the performance of incandescent bulbs in both efficiency and lifetime. Read More...

High voltage buck converters drive high-power LEDs

The LT3474 and LT3475 LED drivers have onboard high voltage NPN power switches and internal sense resistors to minimize board space, reduce component count and simplify design. Read More...

Versatile high power LED driver controller simplifies design

Until recently, driving large arrays of individual LEDs stacked in series usually required an inefficient linear regulator scheme or a more complicated multiple IC switching regulator configuration. Now, there is a single-IC solution which offers low parts count, high efficiency, and supports several operating modes. Read More...

Open standards drive smart lighting and the Enterprise IoT

Open standard-based wireless lighting control systems are a catalyst ushering building controls into the Enterprise Internet of Things (E-IoT). Read More...

Tiny universal LED driver can gradate, blink, or turn on nine individual LEDs

As device designers strive to differentiate their products on the shelf, the number and complexity of lighting effects grows. In this chapter of Analog Circuit Design, we'll see how the LTC3219 9-output universal LED driver can be programmed to individually gradate, blink, or turn on nine individual LEDs using nine 6-bit DAC-controlled LED current sources. Read More...

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Are “beam array” headlights in automotive’s future?

Everyone complains about headlights, but now, someone’s doing something about it. Can smart beam arrays better illuminate the road while causing less glare for other drivers? Read More...

Power Tips #81: Make sure your optocoupler is properly biased

When you are designing an isolated feedback network, you must consider the tolerance of the optocoupler and all other components that determine the large signal gain. Read More...

Designing LEDs for hazardous environments

Discussing LED lighting design for hazardous and electrically challenging environments. Read More...

They're still selling incandescent flashlights?

The typical consumer flashlight now has an ANSI/NEMA standard for defining performance across various parameters, so you can compare units with different light sources. Read More...

LED lighting design considerations for smart cities

Whether for Smart Cities or not, don’t miss any details when designing LED lighting systems and associated sensor hubs. Read More...

Whipping a cheap LED PSU into usable shape

You get what you pay for, and sometimes not even that, but even a cheap Chinese PSU can be improved with some judicious tinkering. Read More...

LED lighting system reliability: Ensuring a robust design

Manufacturers and standards bodies are getting serious about LED lighting reliability. Get your feet wet here, and stay tuned as we continue to explore this topic further. Read More...

Connected lighting may be the IoT killer app

Connected lighting is a huge potential market that might energize the IoT. Read More...

New LED lamp performance specs for California

Light bulb manufacturers who want their LED products to qualify for “Golden State” rebates will now have to meet new efficacy and performance requirements. Read More...

What does QLED mean exactly?

Does adding a Q take the technology a step above LEDs or a step closer to LCDs? It’s a question only Samsung can answer. Read More...

Will the auto industry adopt OLED lighting?

Gone are the days when non-automated retooling dominated the automotive industry, which has made adoption of new technologies much faster. OLEDs may even speed that up. Read More...

Investing in phosphorescent OLED production

OLEDs are taking hold and one company is betting another $15 million that its technology will beat out the competition in a wide range of products. Read More...

A rundown on daytime running lights

Daytime running lights are consistently gaining ground in both the manufacturer-installed and DIY categories. Read More...

Dealing with heat in CSP LED designs

While the benefits of chip-scale packaging LEDs are many, one problem is the ability to deal with heat challenges in small packages with LEDs mounted ever closer together. Here’s a solution that will make life, and heat management, easier. Read More...

Phototherapy could treat skin conditions with LEDs

Applications for LEDs outside of normal on/off lighting can be fascinating. Here is a recent patent grant that involves the use of LEDs in the treatment of skin conditions. Read More...

If it smells fake, it probably is

With all the talk of "fake news" and "alternative facts," can such things happen in business-to-business publications? Read More...

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