SGM3138 Datasheet, PDF (1/11 Pages) SG Micro Corp – Low Dropout Current Source

SGM3138
6-Channel Charge Pump White LED
Driver with Low Dropout Current Source
GENERAL DESCRIPTION
The SGM3138 is a high performance white LED driver. It
integrates current sources and automatic mode selection
charge pump. The part maintains the high efficiency by
utilizing a 1×/1.5× fractional charge pump and low
dropout current sources. The small equivalent 1× mode
open loop resistance and ultra-low dropout voltage of
current source extend the operating time of 1× mode and
optimize the efficiency of Li-ion battery in white LED
applications.
The SGM3138 supports up to 6 white LEDs and
regulates a constant current which the initial value can be
set by an internal resistor. The part implements a 4-bit
DAC for brightness control. Users can easily configure
the LED current from 1.25mA to 20mA by a serial pulse.
The dimming of white LEDs current can be achieved by
applying a pulse signal to the EN/SET pin. There are
totally 16 steps of current could be set by users. The
operating voltage range is 2.7V to 5.5V. Internal soft-start
circuitry effectively reduces the in-rush current while both
start-up and mode transition.
FEATURES
 Input Voltage Range: 2.7V to 5.5V
 Drives Up to 6 LEDs at 20mA Each
 One Single Wire Interface
 16-Step Brightness Control
 High Efficiency by Fractional Conversion with
1× and 1.5× Modes
 Switching Frequency: 1MHz
 Regulated Output Current with ±5% Matching
 Internal Soft-Start Limits Inrush Current
 Low Input Ripple and Low EMI
 Over-Current and Over-Temperature Protection
 Under-Voltage Lockout with Hysteresis
 Available in Green TQFN-3×3-16L Package
APPLICATIONS
Mobile Phone, DSC, MP3
White LED Backlighting
LCD Display Supply
The SGM3138 is available in Green TQFN-3×3-16L
package and is rated over the -40℃ to +85℃ temperature
range.
SG Micro Corp
www.sg-micro.com
REV. A. 4