This paper proposes a MultiTrack power conversion architecture that represent a new way of combining switched-capacitor circuits and magnetics. The MultiTrack architecture reduces the voltage ratings on devices, reduces the voltage regulation stress of the system, improves the component utilization, and reduces the sizes of passive components. This architecture is suitable for power conversion applications that require both isolation and wide voltage conversion range. An 18 V to 80 V input, 5 V, 15 A output, 800 kHz, 0.93 inch2 (1/16 brick equivalent) isolated dc-dc converter has been built and tested to verify the effectiveness of this architecture. By utilizing GaN switches, operating at higher frequency, and employing the MultiTrack architecture, the prototype converter achieves a power density of 453 W/inch3 and a peak efficiency of 91.3%. This power density is 3x higher than the power density of the state-of-the-art commercial converters with comparable efficiency performance across the wide operation range.