SiC features 10x the breakdown field strength compared with silicon, resulting in breakdown voltages in the thousands of volts. In addition, ON resistance per unit area is considerably lower, significantly improving power loss. In order to minimize the increase in ON resistance associated with higher breakdown voltages, silicon IGBTs are primarily used. However, SiC has been shown to provide superior high-speed switching performance.
Body diodes in SiC MOSFETs that consist of a pn junction feature a shorter minority carrier lifetime. This makes it difficult to see the accumulation effect of the minority carriers, enabling ultra-high-speed recovery performance (tens of ns) equivalent to SBDs.
Body diodes in SiC MOSFETs that consist of a pn junction feature a shorter minority carrier lifetime. This makes it difficult to see the accumulation effect of the minority carriers, enabling ultra-high-speed recovery performance (tens of ns) equivalent to SBDs. Also, the recovery time is constant and independent of forward injection current - similar to SBDs (if dI/dt is constant).
The bandgap of SiC is 3x that of silicon, resulting in a 3V larger rise voltage in the pn diode and consequently a relatively large forward voltage drop. However, since reverse conduction in the bridge circuit etc. is possible due to gate ON signal input during commutation, substantive steady-state loss should not be an issue.
Since the diode is connected internally, it is not possible to externally isolate characteristics. However, because the Vf of the SiC SBD is small, forward current within the normal operating range will flow only through the SiC SBD. Therefore, the If-Vf and reverse recovery characteristics can be considered a part of the SiC SBD characteristics.
The exposed metal sections (heat sink at back of package and bare metal section at the notch) are at the same potential as the drain. As a result, for products where the package includes a backside heat sink the creepage distance may be insufficient. Therefore, we ask that the user confirm the guidelines for creepage distance, taking into account the operating environment.