The new second generation 650V SiC SBDs, improved with both surge forward current (IFSM) and switching loss (Ron*Qc) [Note 1], realizes higher power supply efficiency.
Power factor correction (PFC) for high efficiency power supply, Chopper circuit, and free wheel diode for switching element
New second generation 650V SBDs Line-up / Characteristics
|Absolute Maximum Ratings||Electrical Characteristics|
|Forward DC Current
||Non-repetitive Peak Forward Surge Current
||Total Power Dissipation
||Total Capacitive Charge
Test Conditions/Part Number
|-||@ Half-sine Wave
0.25 to 1.0
|@VR=1 V||@VR=400 V|
[Notes 1] RON: Anode-cathode on-resistance, Qc: Total capacitive charge
Due to a major shift in customer focus to environmentally friendly, clean energy sources, market demand is increasing for power devices that will make it possible to achieve low-loss and high-efficiency power conversion. Silicon carbide (SiC), a wide-gap semiconductor, is expected to be a material for the next-generation high-voltage, low-loss power devices because its critical breakdown field is more than eight times that of silicon (Si).
While Si SBDs are available with a VRRM of only up to 200 V, Toshiba's new SiC-based Schottky barrier diodes (SBDs) provide higher reverse voltage (VRRM) because of low leakage current in the high-temperature region. SiC Schottky Barrier Diodes are ideal for power conversion applications such as server power supplies and solar power conditioners. At high voltage and high current, the operation of SiC Schottky Barrier Diodes is more stable than that of the conventional Si SBDs. Therefore, SiC Schottky Barrier Diodes help to significantly reduce the loss of power through heat.
● Physical property comparisons between Si and SiC
|Band gap||1.12 eV||3.26 eV|
|Electron mobility μ||1400 cm2/Vs||1000 cm2/Vs|
|Relative dielectric constant ε||11.8||9.7|
|Critical breakdown field E||0.3 MV/cm||2.5 MV/cm|
|Transistor performance limit
Ron・A (@600 V)
|70 mΩ・cm2||0.14 mΩ・cm2|
Easy to process
|Easy to reduce on-resistance
Low leakage current at high temperatures
Easy to create designs with high
SiC Schottky Barrier Diodes are majority carrier devices and have the same structure as Si SBDs. Fabricated with a wide-gap semiconductor, SiC Schottky Barrier Diodes exhibit low leakage current even in the high-temperature region, making it possible to maintain stable operation at high voltage and high current. Toshiba's SiC Schottky Barrier Diodes have a Junction Barrier Schottky (JBS) structure to further reduce leakage current.
Theoretically, SiC Schottky Barrier Diodes provide zero reverse recovery time, trr, because of the Schottky structure and majority carrier operation. In practice, however, SiC Schottky Barrier Diodes also have a reverse recovery region. Its reverse recovery time, trr, is as short as 20 ns (at Ta = 25°C), compared with Si high-efficiency diodes (HEDs) with a trr of 40 ns.
Comparison of Reverse Recovery Time, trr, Between a SiC Schottky Barrier Diode and a Si HED Diode (Tj = 150˚C)
Because SiC Schottky Barrier Diodes are majority carrier devices, their electrical performance is theoretically independent of temperature. Thus, SiC Schottky Barrier Diodes exhibit excellent performance even in the high-temperature region.
Reverse Recovery Time (trr)/Reverse Recovery Current (Irr) vs. Temperature
SiC Schottky Barrier Diodes offer low total loss, which consists of conduction loss and switching loss. Therefore, SiC Schottky Barrier Diodes can switch at high frequencies, making it possible to reduce the size of power supplies.
Total Loss vs. Frequency
* HED: High-Efficiency Diodes
There is a trade-off between the forward voltage (VF) and reverse current (IR) of an SiC Schottky Barrier Diode. Toshiba is endeavoring to improve the VF-IR trade-off by optimizing the device structure. Our SiC Schottky Barrier Diodes exhibit low loss even in the high-temperature region and thus help reduce power loss.
Toshiba's SiC Schottky Barrier Diodes have low dependence on forward voltage, VF, making it possible to reduce conduction loss in the high-temperature region.
Forward Voltage (VF) vs. Temperature
|Absolute Maximum Ratings||Electrical Characteristics (Ta=25℃)||TO-220-2L||TO-220F-2L||TO-247||TO-3P(N)|
|Typ.||Max||Test Conditions @IF(A)||Max||Test Conditions @VR(V)|
雖然SiC SBD的導通損耗高於Si FRD，但SiC SBD具有較低的切換損耗，所以總體損耗有所降低。