Design & Manufacture
LittelFuse – LED protectors keep LED strings working when an individual LED fails (PLED6M)Aug 29 2012 - Design & Manufacture [More Design & Manufacture Articles]
A new line of open LED protectors optimized to provide superior protection against open-circuit LEDs, has been developed by Littelfuse.
The PLED6M Series LED protector is designed to provide a switching electronic shunt path when an LED in an LED string fails as an open circuit. This ensures that the entire array of LEDs will continue providing illumination even if a single LED in the string fails. The new LED protectors provide greater lighting reliability in applications where uninterrupted illumination is critical, such as street, subway, runway, and tunnel lighting, as well as vehicle headlights, roadside warning lights, and outdoor signage.
The PLED6M Series is designed for use with 1W LEDs, nominally 350mA, 3V. A low turn-on voltage of 7.5V (max) allows for fast switching after an LED opens. In addition, the on-state (bypass) voltage of 1.2V (max) reduces the steady state power dissipation following an LED open failure and is housed in a small form factor Powermite package.
Key benefits for LED array designers :
* The devices provide an electronic shunt/bypass for open LEDs, allowing LED strings to keep functioning, even if one LED in the set fails as an open circuit. * They automatically reset if the LED heals itself or the power is cycled, for low maintenance and high reliability. * The device’s low-profile small-footprint POWERMITE package provides maximum heat dissipation and greater layout flexibility, making it ideal for dense board applications. * The devices can support high-brightness in outdoor LED applications and are RoHS compliant.
Chad Marak, manager of the Littelfuse PLED product line, said: “The PLED6M open LED protector will appeal to anyone who designs and manufactures outdoor lighting or signage that requires strings of high-brightness LEDs with high reliability and low maintenance requirements.”