In summary, the SEPIC converter operates over a wide input voltage range. Cost, size and performance benefit when using coupled inductors compared to using two discrete inductors. To facilitate inductor selection, selection guides are available to help to choose the inductor needed, or for higher power circuits the Versa-Pac calculator will recommend the correct part. The SEPIC topology is extensively used in hand held, battery operated products because this topology extends battery life by working in both Buck and Boost modes. When the battery input voltage is higher than the circuit’s operating voltage, the SEPIC converter operates as a buck converter to step-down the input voltage. When the battery voltage drops below the circuit’s operating voltage, the SEPIC converter operates in a boost converter mode, stepping the voltage up and allowing the system to operate until the battery is exhausted. This boost mode allows for extracting the longest operating time between battery charges.