The NCP1450A series are PWM step-up DC-DC switching controller that are specially designed for powering portable equipment from one or two cells battery packs. The NCP1450A series have a driver pin, EXT pin, for connecting to an external transistor. Large output currents can be obtained by connecting a low ON-resistance external power transistor to the EXT pin. The device will automatically skip switching cycles under light load condition to maintain high efficiency at light loads. With only six external components, this series allows a simple means to implement highly efficient converter for large output current applications. Each device consists of an on-chip Pulse Width Modulation (PWM) oscillator, PWM controller, phase-compensated error amplifier, soft-start, voltage reference, and driver for driving external power transistor. Additionally, a chip enable feature is provided to power down the converter for extended battery life. The NCP1450A device series are available in the TSOP-5 package with five standard regulated output voltages. Additional voltages that range from 1.8 V to 5.0 V in 100 mV steps can be manufactured.