GENERAL DEscriptION
The SGM3140 is a current-regulated buck/boost charge pump LED driver capable of driving 500mA output current. It is ideal for powering high brightness LEDs for camera flash applications. The SGM3140 has 1×/2× operation mode to control the output current for flash and torch modes.
The supply voltage operates from 2.7V to 5.5V and is well suited for various applications powered by a 1-cell Li-Ion battery, as well as 3-cell or 4-cell NiCd, NiMH or Alkaline batteries. The SGM3140 automatically converts between boost and buck modes. Therefore, it ensures that LED current cannot be restricted by the forward voltage. High switching frequency makes it easy to use tiny components. Small 0603 current sense resistors can be used due to the low FB reference voltage.
The SGM3140 provides very low shutdown current and soft-start function. Built-in soft-start circuitry avoids excessive inrush current during startup. The SGM3140 also includes a comprehensive set of protection features such as over-voltage protection, over-current protection and thermal shutdown.
The SGM3140 is available in a Green TDFN-3×3-10L package and is specified over an ambient temperature range of -40℃ to +85℃.
FEATURES
Input Voltage Range: 2.7V to 5.5V
Up to 500mA Output Current
Up to 90% Efficiency in Torch Mode
Programmable Flash Current
Automatic Buck/Boost Mode Conversion
No External Inductors
High Switching Frequency: 2.2MHz
Low Reference for Low Loss Sensing: 47mV
Less than 1μA Shutdown Current
Automatic Soft-Start for Reducing Inrush Current
Low Input and Output Ripple and Low EMI
Protection Features
Output Over-Voltage Protection
Over-Current Protection
Thermal Shutdown
Available in a Green TDFN-3×3-10L Package
APPLICATIONS
White LED Torch or Flash for Cell
Phones, Camcorders and DSCs
Generic Lighting, Strobe and Flash Applications
White LED Backlighting
General Purpose High Current Boost