The AP1624 is multi-functional step-up DC/DC controllers. Large output current is possible using an externally connected N channel MOSFET, coil, and diode. Output voltage (VOUT)is programmable with 1.23V of standard voltage supply internal, and using externally connected components, output voltage (FB) can be set up at will. With a 300KHz switching frequency, the size of the external components can be reduced. Control switches from PFM to PWM during light loads with the AP1624(PFM/PWM switchable)and the series is highly efficient from light loads to large output currents.