A new high efficiency and low profile on-board DC/DC converter for digital car audio amplifier is proposed. The proposed converter shows the continuous input current, no DC excitation current of the transformer, the minimized electro-magnetic interference (EMI), no output inductor, and the low voltage stress of the secondary rectifier diodes. The 60 W industrial sample of the proposed converter is implemented for digital car audio amplifier and the measured efficiency is 88.3% at nominal input voltage.