EVLG599-250WLLC 400 V - 24 V / 10.5 A DC-DC resonant LLC converter for industrial applications, using STNRG599A, MASTERGAN1L and

This demonstration board is a resonant LLC converter for industrial applications providing minimum size and very high efficiency. It can be used as a DC-to-DC converter or as part of a more complex system using a front-end preconditioner such as a PFC. The board is based on the STNRG599A, a new resonant tank controller implementing the novel phase-shift control method, and on MASTERGAN1L, embedding a GaN transistor-based half-bridge leg and corresponding drivers in the same package. This allows direct interfacing with any kind of SMPS controller.

To achieve high efficiency, secondary-side synchronous rectification is implemented with SRK2001A. The board has no heat sinks on the primary side and offers very reduced dimensions. The power density is about 41 W/inch3. Its high efficiency and small size make the board suitable when available space is limited.

The output power of the converter can be up to 250 W at 24 Vdc. The converter provides protections against overcurrent, short-circuit and overvoltage. The STNRG599A integrated HV startup allows powering the IC from AC mains for proper power-up, with no need for auxiliary standby supplies. It can provide current also to another control IC such as, for example, the PFC control IC. The DC input voltage monitoring allows for startup with the correct sequencing of cascaded converters, preventing operation with too low input voltage.

The board consists of a motherboard with the LLC resonant tank and the primary controller, and two daughterboards: one on the primary side with MASTERGAN1L, and another on the secondary side with SRK2001A and the synchronous rectification MOSFETs. Note that the STNRG599A is the IC version with X-capacitor discharge enabled at the HV pin, suitable for adapter applications, while STNRG599B is the IC version with X-capacitor discharge disabled at the HV pin, suitable for lighting applications.