Datasheet Texas Instruments LM3508TL/NOPB — Ficha de datos

LM3508
www.ti.com SNVS494C – APRIL 2007 – REVISED MAY 2013 LM3508 Synchronous Magnetic Constant Current White LED Driver
Check for Samples: LM3508 FEATURES DESCRIPTION The LM3508 is a synchronous boost converter (no
external Schottky diode required) that provides a
constant current output. It is designed to drive up to 4
series white LEDs at 30mA from a single-cell Li-Ion
battery. A single low power external resistor is used
to set the maximum LED current. The LED current
can be adjusted by applying a PWM signal of up to
100kHz to the DIM pin. Internal soft-start circuitry is
designed to eliminate high in-rush current at start-up.
For maximum safety, the device features an
advanced short-circuit protection when the output is
shorted to ground. Additionally, over-voltage
protection and an 850kHz switching frequency allow
for the use of small, low-cost output capacitors with
lower voltage ratings. During shutdown, the output is
disconnected from the input preventing a leakage
current path through the LEDs to ground. The
LM3508 is available in a tiny 9-bump chip-scale
DSBGA package. 1 2 Drives 4 Series White LEDs with up to 30mA
>80% Peak Efficiency
Up to 100kHz PWM Brightness Control …