HT7939

High Current and Performance White LED Driver

Rev 1.10

1

November 3, 2009

Features

Over-current protection circuits

Applications

General Description

The HT7939 is a high efficiency boost converter for driv-

ing White LEDs using current mode operation. The de-

vice is designed to drive up to 39 White LEDs from a 5V

power supply. The White LED current is setup using an

external current setting resistor, which has a low feed-

back voltage of 0.2V to minimise power losses in the re-

sistor which improves efficiency. The Over-voltage

function prevents damage to the IC by turning off the

converter when the LED load is open circuit.

The device includes over current protection, over tem-

perature protection and under voltage protection pre-

venting damage to the device when the output is

overloaded.