SGM3803.pdf
No.11015
Boost DC/DC
● 90% Efficient Synchronous Boost Converter
● Device Quiescent Current: 30μA (TYP)
● Less than 1μA Shutdown Current
● Input Voltage Range: 2.7V to 5.5V
● Output Voltage Clamping: 6V
● Adjustable Output Voltage Up to 5.5V
● Power-Save Mode for Improved Efficiency at Low Output Power
● Load Disconnect During Shutdown
● Low Reverse Leakage Current when VOUT1 > VCC
● 1.8V Logic on EN1 Pin for Control
● Over-Temperature Protection
Negative Charge Pump Inverter
● Up to 200mA Output Current
● Only Three Small 2.2μF to 4.7μF Ceramic Capacitors Needed
● Input Voltage Range: 1.4V to 5.5V
● Low 1.5mA (TYP) Quiescent Current in Active Status
● 950kHz Switching Frequency
● 1.8V Logic on EN2 Pin for Control
● Integrated Active Schottky-Diode for Start-Up into Load
The SGM3803 is a constant frequency, current mode, synchronous step-up switching regulator with 200mA negative charge pump inverter which generates an unregulated negative output voltage from an input voltage ranging from 1.4V to 5.5V. The device is typically used to generate +5V and -5V from battery. High switching frequency minimizes the sizes of inductor and capacitor. Only three external capacitors are required to build a complete charge pump inverter.
Integrated power MOSFETs and internal compensation of boost DC/DC make the SGM3803 simple to use and fit the total solution into a compact space.
The negative charge pump in SGM3803 can deliver a maximum output current of 200mA with a typical conversion efficiency of greater than 80% over a wide output current range.
For light load current, the SGM3803 boost DC/DC enters into the power-save mode to maintain high efficiency. Anti-ringing control circuitry reduces EMI concerns by damping the inductor in discontinuous mode. The SGM3803 boost DC/DC provides true output disconnect and this allows VOUT1 to go to zero volt during shutdown without drawing any current from the input source. The SGM3803 supports 1.8V logic for control. The output voltage of SGM3803 boost DC/DC can be programmed by an external resistor divider. Boost DC/DC and negative charge pump inverter have independent enable control.
