Due to the energy consumption caused by traditional 12V busbar in digital industry, the bus voltage is turning to 48V, posing a new challenge to the voltage regulator. This paper proposes a topology of LLC-TLVR converter, analyses the principles and characteristics, establishes the small signal model and designs the digital control scheme. Finally, a 200W experimental prototype is built, and the maximum efficiency is 87.6%, which verifies its superiority for low-voltage and high-current load.