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| 4 | | 20 | CRDX00DA12E-XM3 THREE-PHASE INVERTERS KIT-CRD-3DD12P BUCK-BOOST EVALUATION KIT CGD12HBXMP DIFFERENTIAL ISOLATED GATE DRIVER • Three topologies • Offer more than twice the power density compared to other Si-based designs • Greater than 98% efficiency Learn more > • Printed Circuit Board (PCB) • (C3M™) 1200V 75mΩ MOSFETs • Heatsink (including mounting clips) • Optimized for Wolfspeed's high-performance XM3 SiC half bridge power modules • User-configurable turn-on and turn-off gate resistors enabling switching loss optimization • Onboard overcurrent, shoot-through prevention, and reverse polarity protection Learn more > Learn more > expensive undertaking. Ideally, an OBC should intelligently sense you're at 30 percent, for example, and cycle down the battery by replenishing your home with its remaining energy, and then recharge the car back to full power. The goal is to a have a bi-directional OBC that moves power back and forth efficiently with minimal loss during transmission, which for electric vehicles is called conduction. Although several solutions are available, Wolfspeed silicon carbide (SiC) MOSFETs offer several advantages over other components in optimizing bi-directional OBCs. The Grid-Powering Opportunity for OBCs OBCs have addressed anxieties over station availability for off-board charging. Although off-board chargers are fast, they're only available at a charging station, and sometimes are proprietary or have limited access. Besides, a visit to a station and the waiting time might not be worth the top up for a daily commute. As much as OBCs offer advantages over off-board charging at a station, they are slower to charge, which means it needs to be done overnight at home or during the day at work, in the same way, most people keep their smartphones powered up. This is why the battery in an OBC vehicle needs to be cycled, which, in turn, makes a case for bi-directionality. In China, this is being sold as a value proposition to customers, as it essentially turns their car into a mobile power bank. Another scenario made possible by bi-directional OBCs is that several vehicles can be linked together in an energy network. This creates a significant source of power to feed a grid, with individuals being able to "buy" energy during the night at low rates and "sell" it back during the day at peak rates. Today's bi-directional OBCs can be either Isolated Gate Bi-Polar Transistor- (IBGT-) or SiC-based. SiC components are the optimal solution for OBCs because compared to Si components, they are smaller, deliver a lower overall system cost, and are more efficient. A SiC Solution for an Efficient Bi-directional OBC Given the benefits of SiC, Wolfspeed, A Cree Company, set out to design a SiC MOSFET-based 6.6kW bi-directional electric vehicle OBC. The goal was to create a high-efficiency bi- directional OBC with high power density and battery capacity that can potentially be employed to support standalone loads and to supplement grid power. This was realized in the form of a digitally controlled prototype with a switching frequency of 67kHz for Continuous Conduction Mode (CCM) totem pole Power Factor Correction (PFC), and 150kHz to 300kHz for a CLLC resonant converter, which was demonstrated with 885W/ cm3 power density exceeding 96.5 percent in peak efficiency.

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