The circuit shown in the figure consists of a system for driving white LEDs (WLEDs) at low voltage, below 4 V, using common batteries for this purpose. The circuit can drive up to 4 LEDs and can be used as backlight or even in low-power lighting systems. The operating curve for currents between 5 and 60 mA shows that operation can be obtained with voltages as low as 2.8 V. More information about this circuit can be obtained in the datasheet available on the Texas Instruments website at www.ti.com.
