SGM3131.pdf
No.10889
? Input Voltage Range: 2.7V to 5.5V
? Drives up to 4 LEDs at 30mA Each
? LED Brightness Control Through 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 1% Matching
? Internal Softstart Limits Inrush Current
? Low Input Ripple and Low EMI
? Over Current and Over Temperature Protected
? Under Voltage Lockout with Hysteresis
? Operating Temperature Range: -40℃ to +85℃
? Available in Green TQFN3×3-16L Package
The SGM3131 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 SGM3131 supports up to 4 white LEDs and regulates a constant current which the initial value can be set by an external resistor. The part implements a 4-bit DAC for brightness control. Users can easily configure the LED current from 0.5mA to 30mA by a serial pulse. The dimming of white LEDs current can be achieved by applying a pulse signal to the EN 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. The load is disconnected from VIN while shutdown and the shutdown current is less than 1μA.
