• PREMA Semiconductor GmbH

Boost Driver for White LEDs

The core of this Boost Driver consists of a step-up converter with current output, which provides an output voltage of typically 3.6 V for white LEDs. The input voltage can be as low as 0.9V, thus allowing a single cell battery operation. For operation of up three LEDs is only one external component needed, which is an inductor. It is recommended to use an inductor value of 22 µH for a maximum battery lifetime (more than 55 hours with an AA alkaline battery). With a 10 µH coil higher currents can be reached for maximum brightness of the white LEDs. The battery current will be reduced to less than 10 µA in case that the supply voltage drops to avoid a deep discharge of the battery. PR4401 offers a maximum current of 22mAand is delivered in a compact SOT23-3 package, for size-sensitive applications also chip on board assembly is possible. PR4401 LED drivers offer a low-cost three-component-solution for example for small LED flashlights or torches. Demo boards and samples are available.