The SPC3501 is a high efficiency, fixed frequency 550KHz, current mode PWM boost DC/DC converter which  could  operate  battery  such  as  input  voltage down to 2.5V.   The converter output voltage can be adjusted  to  a  maximum  of  5.25V  by  an  external resistor  divider.   Besides  the  converter  includes  a 0.08Ω  N-channel  MOSFET  switch  and  0.12Ω P-channel  synchronous  rectifier.   So  no  external Schottky  diode  is  required  and  could  get  better efficiency near 95%. 
           The converter is based on a fixed frequency, current mode,  pulse-width-modulation  PWM  controller  that goes automatically into PSM mode at light load.When converter operation into discontinuous mode, the  internal  anti-ringing  switch  will  reduce interference and radiated electromagnetic energy.  
           The SPC3501 is available in a space-saving SOT-23-6 package for portable application.

Features
?  High Efficiency up to 95%
?  Low R
DS(ON) Integrated Power MOSFET
?  NMOS 80mΩ / PMOS120mΩ
?  Wide Input Voltage Range: 2.5V to 5.5V
?  Fixed 550KHz Switching Frequency
?  Low-Power Mode for Light Load Conditions
?  ±2.0% Voltage Reference Accuracy
?  PMOS Current Limit for Short Circuit Protection
?  Low Quiescent Current
?  Output Ripple under 200mV. (Scope Full 
Bandwidth)
?  Fast Transient Response
?  Built-In Soft Start Function
?  Over-Temperature Protection with Auto Recovery
?  Output Overvoltage Protection
?  Space-Saving SOT-23-6 Package