Size and battery life are important issues for portable devices. White light-emitting diodes (WLEDs) have thus replaced cold cathode fluorescent lamps as backlight sources. Since WLEDs are small and highly efficient, a good WLED backlight driver design can reduce the size of portable devices and extend their operation time. This paper proposes a high efficiency boost WLED driver with an integrated Schottky diode. The DC-DC converter structure allows high efficiency and the on-chip compensator and Schottky diode reduce the board area. The driver also enhances the substrate noise immunity. The simulation results show that the substrate noise was reduced from ±1.8 to ±0.8 V. The driver was fabricated in the TSMC 0.25-μm bipolar-CMOS-DMOS process. For a load of six VLEDs at an input voltage of 4.3 V, the power efficiency was 91.6%.