MAY 16, 2008--Orb Optronix (Kirkland, WA, USA; www.orboptronix.com) has made a significant expansion to its LED test-and-measurement-services laboratory, offering complete optical, thermal, and electrical characterization of light-emitting diodes (LEDs). To deal with the problem of determining the true operational performance of LEDs, Orb Optronix has developed facilities to accurately measure LED spectral output under tightly controlled thermal conditions over a range of forward drive currents with high precision forward voltage monitoring.
The spectral radiant flux of an LED is a function of many variables including temperature, current, and forward voltage, each as a function of time. This leads to additional relevant variables when you include frequency and duty cycle for pulsewidth modulated current control. High-power LED manufacturers are currently specifying optical output of their LEDs under short single current pulse conditions.
Today's high-power LED specification sheets generally assume that the junction temperature is equal to the ambient air temperature of 25°C. Although these tests are easily repeatable, they are not particularly useful to engineers designing LEDs into illumination and display products. LED integrators can now accurately and completely characterize LEDs using Orb's services to solve these complex product-development challenges.