ON Semiconductor Aims to Cure Range Anxiety with SiC
The development of fast-charging EV stations will rely heavily on the use of wide-bandgap semiconductors, which is what ON Semiconductor is aiming for with its new SiC MOSFETs.
Even with the hyperfocus on the electric vehicle (EV) industry, numerous variables are causing stress on pushing them forward. One key stressor is "range anxiety."
In the EV industry, the term range anxiety expresses the feeling of unease consumers have about the limited travel range the vehicles offer.
While a top-tier EV can offer anywhere between 300-400 miles on a single charge, the process of recharging these batteries can take up to 8 hours. Compare that to the 2 minutes it takes to refill your car at a gas station, and it's easy to understand why range anxiety is genuine in the EV world.
Results of Edmund's EV range test. Image used courtesy of Edmunds
A possible solution to helping ease the anxiety is faster charging. However, the effort to develop speedier EV chargers is a technically complex one, so much so that engineers have needed to take entirely new approaches to system development. One particular change has been the abandonment of silicon-based transistors for power applications favoring wide-bandgap semiconductors such as Gallium Nitride (GaN) and Silicon Carbide (SiC).
ON Semiconductor is amongst the companies taking the wide-bandgap approach to EV charging. This week, the company released a new SiC solution that it hopes will enable better, more compact rapid chargers.
Needs for EV Charging
Designers require an extremely high power output to achieve rapid charging of EVs, sometimes exceeding 350 kW. The result of this is that power efficiency has become paramount in these designs, not only for thermal management but also for maximal output.
EVs need extremely high power to enable rapid charging. Image used courtesy of Battery University and Renault
A standard EV charger consists of two main phases: an AC/DC conversion and a DC/DC conversion stage––both of which are generally based on power-efficient switched-conversion techniques. The key to power efficiency in these architectures has high switching frequencies and low ON resistance (RDS(on)) to minimize switching and conduction losses. Along with this, engineers need a device that can withstand extremely high voltages without suffering a breakdown.
Finally, these demands are made even more difficult due to the space constraints imposed by charging locations. Altogether, these stringent demands on power, operating conditions, and size have forced engineers to look beyond standard silicon-based devices for better solutions.
SiC for EVs
With these constraints to EV chargers in mind, wide-bandgap semiconductors, and SiC, in particular, have risen significantly in popularity over the past couple of years.
SiC vs, Silicon material properties. Image used courtesy of STMicroelectronics
For starters, SiC devices benefit from extremely high carrier mobility. This benefit results in significantly faster switching speeds and lower RDS(on) for SiC MOSFETs than its silicon counterpart. With lower switching and conduction losses (almost 100x less), SiC appears to be a much more efficient option in power electronics.
On top of this, due to its wider bandgap, SiC devices have a higher breakdown voltage and higher temperature conductivity than Si. This conductivity means that SiC can operate at hotter temperatures and be subjected to higher voltages, both of which are crucial in power electronics.
By utilizing the benefits of SiC as a semiconductor material, ON Semiconductor aims to improve its MOSFET modules for EV charging.
ON’s New SiC Module
ON Semiconductor made news this week in the EV charging field by releasing a new 2-pack SiC module.
NXH006P120MNF2 Schematic Diagram. Image used courtesy of ON Semiconductor
This new offering contains two 1200 V full SiC MOSFET configured as a half-bridge on the same package, helping save area and eliminate losses due to parasitics. Naturally pushing for the highest efficiency devices it can achieve, ON offers both 10 and 6 milliohms RDS(on) options for this dual-gate module.
Another added feature of this module is a built-in NTC thermistor for temperature monitoring, which could be a valuable addition in extreme temperature power electronics.
Though this is just one small release for EV charging, with the power and area savings that the new module brings, ON Semiconductor hopes to cure range anxiety and enable the next generation of EV chargers based on SiC technology. With steady advancements and innovations such as this, more technology for faster EV charging is sure to come, especially with the Applied Power Electronics Conference (APEC) taking place next week, which will also release more information on ON Semiconductors' use of SiC for EV charging.
Featured image used courtesy of ON Semiconductor
Interested in learning more about recent EV advancements? Find out more in the articles down below.