Cree LED’s precision dimming is a new production technique that addresses unacceptable light output and hue variations when dimming parallel strings of LEDs to low current. These light output variations are caused by normal production variations in characteristics of LEDs and can be reduced substantially with proper system design.
- A novel production technique has been introduced to address the problems of inconsistent light output and hue experienced when dimming LEDs to low current
- With precision dimming, manufacturers gain simplified control over voltage, light output and color rendering
- This method enables precise adjustment of key color rendering parameters while reducing the need for multiple bins
- TM-21 reported L80 >102K hrs lifetimes across all 2835 LEDs
When operated in parallel strings, as is common in many linear LED designs, LEDs driven at relatively low currents (e.g., less than 20 mA for 3-V mid-power LEDs) will exhibit unacceptable light output and hue variations across the strings. These light output variations are caused by normal production variations in characteristics of LEDs and can be reduced substantially with proper system design.
Lighting designers, specifiers, architects and end users have observed this inconsistency issue while dimming in many common linear-style LED designs, including cove accent lighting, wall texture graze lighting, indirect lighting and in some recessed linear general illumination.
Other LED manufacturers tackle LED inconsistency by conducting two rounds of forward voltage sorting. First, they perform sorting during the binning process at the specified current, and then they repeat the sorting at a lower current. However, this approach introduces additional voltage bins that can be challenging to effectively manage during production.
Precision dimming provides manufacturers of no-compromise, specification-grade lighting with a straightforward solution. The precision dimming system offers a total of four bins: J, K, L and M. Moreover, for each combination of CCT (Correlated Color Temperature) and CRI (Color Rendering Index) of an LED equipped with precision dimming, there will consistently be a maximum of two precision dimming bins.
Cree LED tapped into our extensive LED performance and manufacturing knowledge to address this issue of inconsistent LED dimming. Our engineering team has developed a new method to bring consistency for low-input intensity and color performance-critical applications. Industry standard 3-dimensional binning (chromaticity, voltage and flux) is greatly improved by the introduction of a simple fourth dimension that Cree LED calls Precision Dimming.
Precision Dimming provides the easiest solution to manufacturers of no-compromise, specification-grade lighting. There are only four total Precision Dimming bins: J, K, L & M. In addition, each CCT & CRI combination of an LED with Precision Dimming will only ever have two Precision Dimming bins.
