At a RDS(on) value of less than half that of many existing SiC MOSFETs, the 6mohm device provides a robust short-circuit withstand time rating.
There are 9 new device/package options in the 750V SiC FET series, rated at 6, 9, 11, 23, 33, and 44mohms. All are available in the TO-247-4L package while the 18, 23, 33, 44, and 60mohm devices also come in the TO-247-3L.
Complemented by the 18 and 60mohm devices currently available, this 750V expanded series provides more device options, enabling greater design flexibility to achieve an optimum cost/efficiency trade-off while maintaining generous design margins and circuit robustness.
These Gen 4 SiC FETs are a ‘cascode’ of a SiC JFET and a co-packaged silicon MOSFET. Together, these provide the advantages of wide band-gap technology - high speed and low losses with high temperature operation, while retaining an easy, stable, and robust gate drive with integral ESD protection.
The advantages are quantified by Figures of Merit (FoMs) such as RDS(on) x A, a measure of conduction losses per unit die area. Gen 4 SiC FETs achieve the lowest values in the market at both high and low die temperatures.
FoM RDS(on) x EOSS/QOSS is important in hard-switching applications and is half the nearest competitor value. FoM RDS(on) x COSS(tr) is critical in soft-switching applications and device values are around 30% less than competitor parts, rated at 650V compared with UnitedSiC’s at 750V.
For hard switching applications, the integral body diode of SiC FETs is superior in recovery speed and forward voltage drop compared to Si MOSFET or SiC MOSFET technologies. 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.
These SiC FETs are intended for challenging, emerging applications. These include 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.
Established applications will also benefit from use of the devices for an easy boost in efficiency with their backwards compatibility with Si MOSFET and IGBT gate drives and established TO-247 packaging.
