News: Microelectronics
21 March 2023
GaN Systems unveils 11kW/800V on-board charger reference design
At the Applied Power Electronics Conference (APEC 2023) in Orlando, FL, USA (19–23 March), GaN Systems Inc of Ottawa, Ontario, Canada (a fabless developer of gallium nitride-based power switching semiconductors for power conversion and control applications) has unveiled a new GaN-based 11kW/800V on-board charger (OBC) reference design that is claimed to deliver 36% higher power density and up to 15% lower bill of materials (BOM) cost compared with silicon carbide (SiC) transistors.
The OBC combines a three-level flying capacitor topology for a bridgeless totem-pole power factor correction (PFC) structure and dual active bridge in the AC/DC and DC/DC, respectively. The GaN transistors, in the three-level topology with superior switching performance, reduce the transistor voltage stress to half and allow the economical 650V GaN to be used in this and many other 800V applications.
Key features of the OBC design include:
- AC/DC stage peak efficiency >99%, DC/DC stage peak efficiency >98.5%;
- smaller total semiconductor power loss;
- minimized gate ringing, lower noise and ringing during switching transitions;
- improved thermal performance by employing an IMS interface.
GaN power semiconductors increase the efficiency of the OBC by reducing switching losses and power dissipation during operation. This improved efficiency reduces power losses during electric vehicle (EV) charging, making the OBC significantly more energy efficient and cost effective, says the firm. For example, the solution’s higher efficiency reduces the complexity and cost of the cooling system design. The compact and highly efficient design helps to reduce the overall size and weight of the OBC, freeing up space and weight that can be allocated to other areas of the EV design.
“The GaN-powered 800V on-board charger reference design is a major advance that will accelerate GaN adoption in the automotive sector,” believes CEO Jim Witham. “Our new cutting-edge design delivers extraordinary gains in efficiency, power density, cost, thermals and CO2 footprint reduction to deliver a game-changing solution for our automotive customers.”
