GENERAL DEscriptION
The SGM3781 is a highly integrated boost DC/DC converter with 2MHz fixed frequency. High switching frequency makes it easy to use tiny components and optimized for portable photo flash. The SGM3781 is ideal for high power flash LEDs which are suited for mobile phone camera modules and digital still cameras.
The SGM3781 offers excellent flexibility to enter flash mode and movie/torch mode through the ENF and ENM pins respectively. The maximal flash current and movie/torch current are respectively programmed through external resistors (RSETF and RSETM), which can provide simple control for the flash LED solution. When both ENF and ENM pins are driven high, the LED current is set to movie/torch current through RSETM resistor.
The D1 and D2 pins can be tied together to drive higher power single flash LEDs, sinking up to 1.5A continuous current. The integrated thermal regulation in flash mode limits the temperature of the device. It can prevent the device from triggering thermal shutdown and provide the maximum LED output current continuously.
The SGM3781 provides very low shutdown current. It also includes a comprehensive set of protection features such as over-voltage protection, LED open or short protection and thermal shutdown.
The SGM3781 is available in a Green TDFN-3×2-14L package. It operates over an ambient temperature range of -40℃ to +85℃.
FEATURES
Input Voltage Range: 3V to 5V
Up to Total 1.5A or Each 0.75A LED Current
Up to 90% Efficiency
Dual Flash LED Outputs
Tiny Inductor: 1.0μH
2MHz Boost Converter
Separate Flash Mode Enable and Movie/Torch Mode Enable Control Pins
Flash Mode Diming and Movie/Torch Mode Dimming through PWM Signal
Independent Resistors Set Flash Current and Movie/Torch Current Respectively
Integrated Thermal Regulation Control
330kΩ Pull-Down Resistor on ENM and ENF Pins
PWM Dimming Frequency Range: 10kHz to 200kHz
Protection Features
Output Over-Voltage Protection
LED Open or Short Protection
Cycle-by-Cycle Current Limit
Less than 1μA Shutdown Current
Available in a Green TDFN-3×2-14L Package
Temperature Range: -40℃ to +85℃
APPLICATIONS
Portable Equipment