According to the DALI protocol, the dimming curve can be divided into two categories. One is the logarithmic dimming curve and another is the linear dimming curve. Both of them within the range from 0% to 100% is divided into 255 levels (level 0 to level 254).
The range from 0% to 100% is equally divided into 255 levels in terms of the linear dimming.
However, different from linear dimming curves, the logarithmic dimming curve focuses on subdividing low-end output (output below 20%); to be specific, current under the circumstance that the output between 20% and 100% only takes 59 dimming levels.
Standard logarithmic dimming curve defined by DALI protocol is shown below.
1. Logarithmic CurvePlease refers to the above figure. In the case that the light is not dimed to off, percent taken by the minimum output current can be 0.1%.
2. Linear Curve the range from 0% to 100% is divided into 255 levels. In the case that the light is not dimed to off, percent taken by the minimum output current can be 0.4% and the difference between every two levels is 0.039%.
Reference
https://www.moonsindustries.com/article/dali-led-driver
