The AP3003 series of regulators are fixed frequency PWM buck (step-down) DC/DC converter, capable of driving a 3A load with excellent line and load regulation. These regulators include internal frequency compensation and a fixed frequency oscillator so that they are easy to use. A system adopting AP3003 requires a minimum number of external components to work. A standard series of inductors, optimized for use with the AP3003 series, are available from several manufacturers. This feature greatly simplifies the design of switch-mode power supplies. These ICs are available in TO-220-5 and TO-263-5 packages.