A digital brightness controlled white LED driver with I2C-bus interface

We presents a white light emitting diodes (WLEDs) driver based on the boost topology, with digital pulse width modulation and pulse skip modulation, as well as an I²C (Inter Integrated Circuit) communication bus interface. The results of the boost converter show that the chip can drive 2-6 WLEDs when the input voltage varies from 2.7-5.5 V, with the peak efficiency of 84%. The chip can work not only in digital mode with four different brightness level, but also in I²C control mode, in which the brightness of WLEDs are controlled in 256 levels. This simple WLED driver with flexible control mode meets the requirements of low cost, high efficiency backlight applications.