Rosenberg, Klein & Lee
Perceptually linear LED brightness control
A current regulator includes a first current source to provide a reference current varying with a dimming step, and a second current source to generate a drive current for a white LED according to the reference current. The reference current and the dimming step have a relationship identical to or approximating a relationship between luminance and lightness perceived by human eyes. Thus, the white LED is controlled to have a linear variation of the luminance perceived by human eyes when the dimming step is changed.
Richtek Technology Corp.
H Y
H05B Y02B
inventional additional
Shui-Mu Tsung-Wei Kwan-Jen Jien-Sheng
Lin Huang Chu Chen