Holtek Semiconductor HT7938A
The HT7938A is high efficiency boost converter with constant current output for backlight applications in handheld devices. The continuous LED current is set using the device FB pin regulated voltage across an external sense resistor, RFB, connected between this pin and ground. The integrated open load protection feature prevents device damage resulting from open circuit load conditions.| Part No. | HT7938A |
|---|---|
| Datasheet | HT7938A Download |
| Manufacturer |  Holtek Semiconductor |
| Description | High Current and Performance White LED Driver |
| Buy | Stock & Price |
APPLICATIONS
● Cellular phones● PDAs
● DSCs
● Handheld devices
● White LED display backlighting
GENERAL DESCRIPTION
Using a series connection of LEDs provides constant identical LED currents resulting in uniform brightness. A low 300mV feedback voltage minimises power losses in the current setting resistor which provides enhanced efficiency. The HT7938A has a dimming frequency of up to 200kHz, which has excellent linear performance over this dimming frequency range. The device switches at rates of up to 1.2MHz to allow the use of extremely small inductors and filter capacitors. Selection Guide Part No. HT7938A Package SOT23-6 Note: Both lead free and green compound devices are available. Marking 38A-3 (VFB=300mV) Rev. 1.30 1 August 23, 2016 Block Diagram FB O VP O VP P ro te c t 39V R am p 1 .2 M H z O SC O TP SR R Q V IN U V L O = 2 .1 V SW HT7938A BG Pin Assignment PinDESCRIPTION
Pin Name I/O SW I GND ― FB I EN I VOP O VIN I Rev. 1.30 EN GND S O T 2 3 -6 V IN O V P E N 6 5 4 3 8 A -3 T o p V ie w 1 2 3 SW G N D FB Desciption Switching pin.
