REF68020 - Reference Design

LLC converters are power conversion circuits that utilize resonance phenomena, consisting of a primary-side excitation inductance, resonant inductor, resonant capacitor, switching element, and secondary-side rectifier circuit. By employing soft-switching technologies such as ZVS (Zero Voltage Switching) (primary-side switch) and ZCS (Zero Current Switching) (secondary-side switch), switching losses are significantly reduced, achieving high efficiency and low EMI by suppressing switching noise. They are applicable to a variety of power conversion circuits.

LLC converters that accept DC 400V input are used in applications where the DC voltage is converted from a commercial AC power input via a PFC (Power Factor Correction) and then converted to the voltage required by the system for distribution (server power supplies, industrial power supplies, PV hybrid inverters, ESS, UPS, xEV OBC (onboard charger), etc.), as well as for voltage conversion from the 400V battery of xEVs (xEV DC-DC converters, etc.). The secondary-side full-bridge rectifier circuit is a topology commonly used for relatively high power (up to several tens of kW) and relatively high output voltage (>48V).

This reference design is a DC 390V input, 48V output, 2.5kW LLC converter that incorporates Nuvoton Technology's high-resolution 32-bit MCU (KM1M7CF0) for power control and uses SiC MOSFETs as the primary switching element.

For more details about the board, please contact the following:
https://www.nuvoton.com/applications/power-energy/llc-reference-board/