Holtek Semiconductor HT7939
The HT7939 is a high efficiency boost converter for driving White LEDs using current mode operation. The device 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 feedback voltage of 0.2V to minimise power losses in the resistor which improves efficiency.| Part No. | HT7939 |
|---|---|
| Datasheet | HT7939 Download |
| Manufacturer |  Holtek Semiconductor |
| Description | High Current and Performance White LED Driver |
| Buy | Stock & Price |
FEATURES
● Input range from 2.6V~5.5V● Built-in Power MOSFET
● Can drive up to 39 White LEDs with a 5V input
● Low standby current: 0.1mA (typ.) with VEN low
● Integrated Over-voltage, Over-temperature and
● Under voltage lock-out protection
● 1.2MHz fixed switching frequency
● High efficiency - up to 90%
● 6-pin SOT23-6 package Over-current protection circuits
APPLICATIONS
● Display Backlighting● LED lighting Automatic DVD player Digital photo frame Handheld computer
GENERAL DESCRIPTION
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 temperature protection and under voltage protection preventing damage to the device when the output is overloaded. Rev 1.10 1 November 3, 2009 HT7939 Block Diagram 32V Pin Assignment S O T 2 3 -6 V IN 6 O V P 5 E N 4 T o p V ie w 1 S W 2 G N D 3 F B PinDESCRIPTION
Pin No. 1 2 Pin Name SW GNDDESCRIPTION
Switching pin. Internal power MOSFET drain.
