Design of High-Stability Driver for White LED

The driving technology is a very important factor influencing the output performances of white LED (WLED).This paper proposes a kind of high-stability driver for WLED based on constant-current and constant-luminance. The working characteristics of WLED and the principle of driving WLED are introduced in this paper. The newly designed driver works in a mode of constant current LDO and it is feedback controlled by the output of WLED to obtain highly stable luminance. Finally, a test circuit is set up to validate the proposed scheme and some experiments are carried out. The results show that the driving current maintains nearly constant and the luminance of WLED is of high accuracy.