SGM3140 Datasheet, PDF (1/14 Pages) SG Micro Corp – Charge Pump LED Driver

SGM3140
500mA Buck/Boost
Charge Pump LED Driver
GENERAL DESCRIPTION
The SGM3140 is a current-regulated charge pump
ideal for powering high brightness LEDs for camera
flash applications. The charge pump can be set to
regulate two current levels for Flash and Torch modes.
The SGM3140 automatically switches modes between
step-up and step-down ensuring that LED current does
not depend on the forward voltage. It switches at
2.2MHz, allowing the use of tiny components. The
supply voltage ranges from 2.7V to 5.5V and is ideally
suited for all applications powered by a single Li-ion
battery cell or three to four NiCd, NiMH, or Alkaline
battery cells.
The SGM3140 also features a very low shutdown
current, an automatic soft-start mode to limit inrush
current, as well as over-current, over-voltage and
over-temperature thermal shutdown control.
A low current-sense reference voltage (47mV) allows
the use of small 0603 current sensing resistors.
The SGM3140 is available in Green TDFN-3×3-10L
package and is specified over an ambient temperature
range of -40℃ to +85℃.
APPLICATIONS
White LED Torch, Flash for Cell
Phones, DSCs and Camcorders
White LED Backlighting
Generic Lighting, Flash and Strobe Applications
General Purpose High Current Boost
FEATURES
● Output Current Up to 500mA
● Up to 90% Efficiency in Torch Mode
● Adjustable Flash Mode Current
● Automatic Buck/Boost Mode Switchover
● Input Voltage Range: 2.7V to 5.5V
● Minimum External Components: No Inductors
● High Frequency Operation: 2.2MHz
● Low 47mV Reference for Low Loss Sensing
● I_Q < 1μA in Shutdown
● Automatic Soft-Start Limits Inrush Current
● Low Input and Output Ripple and Low EMI
● Output Over-Voltage Protection
● Over-Current and Over-Temperature Protection
● Available in Green TDFN-3×3-10L Package
TYPICAL APPLICATION
VIN
2.7V to 5.5V
CIN
4.7μF
CF
1μF
TORCH/FLASH
ENABLE
1
VIN
2 _C1
10
VOUT
9
PGND
COUT
1μF
SGM3140
3
C2
8
SGND
4
FLASH
7
FB
5 _EN
6
RSET
RSET
86.6kΩ
WLED
RSENSE
0.33Ω
SG Micro Corp
www.sg-micro.com
REV. A. 2