Chris Bailey, Director of Hubbell Lighting’s Lighting Solutions Center, writes an interesting blog post about how to evaluate LED luminaires based on drive current and current density. He writes:

“When evaluating the working stresses of a semiconductor device, such as an LED, the output current from the power supply or the current delivered to the circuit board, LED string and LED package are of little consequence without associating these values to the device ratings. With respect to power, the electrical metric that is most closely associated with LED performance and lifetime is current density. Performance metrics such as efficacy, lumen maintenance and color point stability depend largely upon the designed current level (or current density) of the LED, which may be related to the physical size of the LED die or electrical arrangement of multiple die within an LED package.”

Read the rest here.