UnitedSiC has added nine 750V silicon carbide devices with on resistance as low as 6mΩ. The 6mohm device also provides a robust short-circuit withstand time rating of 5μs.
The series started with 18 and 60mΩ 750V devices in December. “Previously we had the 650V 7mO which was the lowest, not only reducing the RDS on but increasing the blocking voltage as we are looking to give designers more head room,” said Said Chris Dries, President and CEO of UnitedSiC. “When you build out the portfolio there’s qualification time, and we were further along for the 18 and 60 for high volume sockets.”
“We’ve increased the headroom from 650V from 750V and given the designers flexibility so as well as the lowest rds on we have flexibility to either go for efficiency or optimise for cost. The move to 750V is driven by the 450 to 500V bus voltages that the automotive designers are moving to,” he said.
The new 750V SiC FET series is rated at 6, 9, 11, 23, 33, and 44mohms and available in low resistance TO-247-4L packaging. The 18, 23, 33, 44, and 60mΩ devices also come in a more traditional TO-247-3L package.
“We have seen a lot of people transition to the improved switching on the 4L Kelvin connector parts. These operate from all SiC IGBT and MOSFET gate drivers from 0V to 12V with a 5V threshold,” said Dries. “What you will be looking at in the future is additional package types that can accommodate lower rds on.”
These fourth generation SiC FETs are a ‘cascode’ of a SiC JFET and a co-packaged silicon MOSFET with a figure of merit for RDS(on) x EOSS/QOSS that is half the nearest competitor value for hard switching applications. The RDS(on) x COSS(tr) is critical in soft-switching applications and UnitedSiC device values are around 30 percent less than other 650V parts
Other advantages incorporated into the Gen 4 technology are reduced thermal resistance from die to case by advanced wafer thinning techniques and silver-sinter die-attach. These features enable maximum power output for low die temperature rise in demanding applications.
The devices are aimed at traction drives and on- and off-board chargers in electric vehicles and all stages of uni- and bi-directional power conversion in renewable energy inverters, power factor correction, telecoms converters and AC-DC or DC-DC power conversion generally.
Pricing for the 750V Gen 4 SiC devices range from $4.15 for the UJ4C075044K3S, to $23.46 for the UJ4SC075006K4S.