GaN Systems unveils 800-V OBC reference design

Gan Systems has announced at APEC 2023 a new GaN-based 11-kW/800-V on-board charger (OBC) reference design that delivers 36% higher power density and up to 15% lower bill-of-materials (BOM) cost compared to silicon carbide (SiC) transistors, according to the company. The improved efficiency of the 800-V OBC reference design reduces power losses during electric vehicle (EV) charging, resulting in higher efficiency and lower cost.

(Source: Gan Systems)

The OBC combines a three-level flying capacitor topology for a bridgeless totem-pole PFC structure and a dual active bridge in the AC/DC and DC/DC, respectively. The GaN transistors, offering high switching performance, reduce the transistor voltage stress to half, said GaN Systems, and allows the 650-V GaN to be used in many 800-V applications.

The company said using GaN transistors in an 800-V OBC is a “revolutionary innovation that sets this 11-kW/800-V solution apart from competitors” and a “game-changing solution.”

Key features include an AC/DC stage peak efficiency of >99%, a DC/DC stage peak efficiency of >98.5%, lower total semiconductor power loss and minimized gate ringing, lower noise and ringing during switching transitions. It also offers improved thermal performance by using an IMS interface.

By reducing switching losses and power dissipation during operation, GaN power semiconductors increase the efficiency of the OBC by reducing power losses during EV charging, said GaN Systems. One benefit cited is a reduction in the complexity and cost of the cooling system, which helps reduce the size and weight of the OBC. As a result, the size and weight savings can be allocated to other areas of the EV design.