The OBC is capable of delivering 36% higher power density and up to a 15% lower Bill of Materials (BOM) cost compared to silicon carbide (SiC) transistors.
Utilising GaN transistors in an 800V OBC is described as a ‘revolutionary innovation’ by GaN Systems that sets this 11kW/800V solution apart from many of its competitors.
Delivering improved power density and a lower BOM cost, the OBC combines a three-level flying capacitor topology for a bridgeless totem-pole PFC structure and dual active bridge in the AC/DC and DC/DC, respectively. The GaN transistors, in the three-level topology with improved 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:
- 36% higher power density compared to silicon carbide
- 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 EV charging, making the OBC significantly more energy-efficient and cost-effective.
For instance, the solution’s higher efficiency reduces the complexity and cost of the cooling system design, while the compact and highly efficient design helps 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,” said Jim Witham, CEO of GaN Systems. “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.”
