<p>This paper presents a dc-dc converter that can achieve efficient power conversion with a wide-output-range. The converter adds active switches, diodes, and inductors to the outputs of isolated dc-dc converters to realize a wide output voltage range. Besides, an interval modulation method is applied to this converter. The input voltage and the duty ratios of the active switches are controlled to modulate the output voltage in the different intervals. With this approach, high efficiency in the whole output voltage range can be achieved. The operating principles and modulation method are illustrated. An experimental prototype is built to verify the effectiveness of the proposed converter.</p>