Full-Bridge Converter Reference Design 

Ideal for EV infrastructure and high-power applications, this design empowers engineers with scalable performance and proven reliability.

The STDES-6KWHVDCDC reference design from STMicroelectronics is a high-performance 6 kW high-voltage DC-DC converter optimized for electric vehicle (EV) charging infrastructure. It serves as a valuable design aid for engineers developing power conversion systems in automotive, industrial, and renewable energy applications. This reference design demonstrates how advanced digital control techniques and state-of-the-art power devices can be integrated into a compact and efficient solution for high-voltage energy conversion. Its flexible architecture, high efficiency, and wide output range make it highly relevant to engineers seeking scalable and reliable power delivery systems.

At the core of the STDES-6KWHVDCDC is a fully digital, full-bridge LLC resonant converter architecture, providing high efficiency and design versatility. The system features two hardware configurations—a dual transformer variant optimized for narrower voltage ranges (200–500 V or 500–1000 V depending on the winding configuration), and a single transformer variant designed for a broader output voltage span of 200–1000 V. Both versions share the same PCB, allowing designers to adapt the magnetic components according to system needs without redesigning the board layout.

– Advertisement –

Key to the design’s efficiency is a patented control scheme that enables frequency foldback. This technique maintains high efficiency—up to 98%—across varying load and output voltage conditions. Silicon carbide (SiC) diodes, specifically the STPSC40H12CWL, are used in the output rectification stage to ensure fast switching and reduced losses. For the LLC switching stage, ST employs the STW40N95DK5 MDmesh DK5 Power MOSFETs, chosen for their high-voltage handling and low RDS(on) characteristics.

The digital control is managed by the STM32G474RET6 microcontroller, which offers advanced timer features, analog peripherals, and computational capabilities tailored for power conversion tasks. The control logic drives the power stage through isolated gate drive transformers and PM8834MTR gate driver ICs, ensuring robust signal integrity and isolation. The auxiliary power supply is referenced to the secondary ground and supports the gate drivers, MCU, and signal conditioning circuitry.

– Advertisement –

This reference design also emphasizes safety, incorporating comprehensive protection mechanisms suitable for demanding EV charging environments. It demonstrates how ST’s power and control products can be integrated to achieve robust, compact, and efficient power electronics systems. With formal testing validating its performance, the STDES-6KWHVDCDC offers engineers a ready-to-use blueprint for high-voltage DC-DC conversion in EV charging and other high-power applications.

ST Mircoelectronics has tested this reference design. It comes with a bill of materials (BOM), schematics, assembly drawing, printed circuit board (PCB) layout, and more. The company’s website has additional data about the reference design. To read more about this reference design, click here.