Holtek Semiconductor HT7938
HT7938 is high efficiency boost converter with constant current output to provide backlight in handheld devices. The continuous LED current is set with FB pin regulated voltage across an external sense resistor (RFB) connected from that pin to ground. The built-in open load protection prevents the damage resulting from an open circuit condition.| Part No. | HT7938 |
|---|---|
| Datasheet | HT7938 Download |
| Manufacturer |  Holtek Semiconductor |
| Description | High Current And Performance White LED Driver |
| Buy | Stock & Price |
FEATURES
● Efficiency up to 85% at VIN=3.6V, 9LEDs,● Tiny inductor and capacitors
● Up to 9 strings White-LED
● Tiny 6-lead SOT23-6 package
● Built in OVP, OCP, OTP, UVLO protection ILED=20mA
● 1.2MHz fixed switching frequency
● Low Standby Current: 0.1mA, VEN=0V (typ.)
● Matches LED current
APPLICATIONS
● Cellular phones● PDAs
● DSCs
● GPS
● Handheld devices
● White LED display backlighting
GENERAL DESCRIPTION
Series connection of LEDs provides constant identical LED currents resulting in uniform brightness. Low 200mV feedback voltage minimizes power loss in the current setting resistor for better efficiency. HT7938 switches at rates up to 1.2MHz to allow the use of extremely small inductor and filter capacitor. Block Diagram 36V Rev 1.00 1 November 11, 2009 HT7938 Pin Assignment V IN 6 O V P 5 E N 4 T o p V ie w H T 7 9 3 8 S O T 2 3 -6 -A 1 S W 2 G N D 3 F B PinDESCRIPTION
Pin Name EN GND I/O I ¾DESCRIPTION
Shutdown & Dimming control input. Don¢t allow this pin to float. Signal Ground.
