SGM3140B.pdf
No.10929
● 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
● IQ < 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
The SGM3140B 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 SGM3140B 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 SGM3140B 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-thermal shutdown control. A low current sense reference voltage (47mV) allows the use of small 0603 current sensing resistors.
