GENERAL DEscriptION
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 range of 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. The device requires only three external capacitors for a complete DC/DC charge pump inverter. Integrated power MOSFETs and internal compensation of boost DC/DC make the SGM3803 simple to use and optimized for compact solutions.
The negative charge pump inverter of the SGM3803 is capable of providing 200mA output current. The typical conversion efficiency exceeds 80% over a wide output current range.
The SGM3803 boost DC/DC enters the power-save mode at light loads 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, thus allowing 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 the boost DC/DC can be programmed by an external resistor divider. Boost DC/DC and negative charge pump inverter have independent enable control.
The device is available in a TDFN-3×3-12L package. It operates over an ambient temperature range of -40℃ to +85℃.
FEATURES
Boost DC/DC
Input Voltage Range: 2.7V to 5.5V
Up to 5.2V Adjustable Output Voltage
Output Voltage Clamping: 6V
90% Efficient Synchronous Boost Converter
Quiescent Current: 30μA (TYP)
Less than 1μA Shutdown Current
mproved Light Load Efficiency with Power-Save Mode (PSM)
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
Input Voltage Range: 1.4V to 5.5V
200mA Output Current Capability
only Three Small 2.2μF to 4.7μF Ceramic Capacitors are Required
Low Quiescent Current in Active Status: 1.5mA (TYP)
Switching Frequency: 950kHz (TYP)
1.8V Logic on EN2 Pin for Control
Integrated Active Schottky Diode for Startup into Load
APPLICATIONS
Single-Cell Li Battery Powered Products
Portable Audio Players
Cellular Phones
Personal Medical Products