Page 50 - EE Times Europe Magazine | March 2020

50 EE|Times EUROPE — Boards & Solutions Insert

MOTOR CONTROL
CoolSiC MOSFET Motor Drives Evaluation

Board for 7.5-kW Output

By Maurizio Di Paolo Emilio

nfineon Technologies has developed an Figure 1:
evaluation board for motor control appli- Applications for wide-
cations that includes a three-phase SiC bandgap semiconductors
Imodule. In particular, it uses the power of (Image: Infineon Technologies)
CoolSiC MOSFET modules in electric drives.
The board supports customers during their
first steps in designing applications with the
FS45MR12W1M1_B11 six-pack power module
and the EiceDRIVER 1EDI20H12AH 1,200-V
isolated gate driver. The module has a rated
1,200-V block voltage with a typical on-state
resistance of 45 mΩ. It is optimized for motor
drive applications with very high-frequency
switching operation.

COOLSiC MOSFET
Silicon carbide (SiC) is a compound of silicon
and carbon with an allotropic variety. The
advantages of SiC include:
• bandgap of 3.3 eV, versus 1.2 eV for silicon;
• breakdown field of 2.2 MV/cm, compared
with 0.3 MV/cm for silicon;
• thermal conductivity of 4.9 W/cm*K (1.5
W/cm*K for silicon); and
• electron drift velocity of 2*10 cm/s,
7
compared with 1*10 cm/s for silicon.
7
With SiC’s 10× higher breakdown field, the
active zone can be made much thinner, and
many more free carriers can be incorporated.
As a result, conductivity is substantially higher.
The material properties of SiC enable the
design of fast-switching unipolar devices as
opposed to bipolar IGBTs. Wide-bandgap–based
power devices such as SiC diodes and transistors
are established elements for power electronics
design. MOSFETs, meanwhile, are commonly
accepted to be the concept of choice (Figure 1).
Based on these SiC material advantages,
SiC MOSFETs are becoming an attractive
switching transistor for high-power applica-
tions, such as solar inverters and off-board Figure 2: Diagram of the FS45MR12W1M1_B11 module (Image: Infineon Technologies)
electric vehicle (EV) chargers. Thanks to the
specific trench structure, CoolSiC MOSFETs competing silicon and SiC solutions, CoolSiC continuous-conduction–mode totem-pole
increase channel mobility as well as improve MOSFETs at 650 V offer benefits that include power factor correction (PFC).
gate-oxide reliability. switching efficiency at higher frequencies and SiC MOSFETs with blocking voltages of
Infineon recently introduced CoolSiC outstanding reliability, according to Infineon. 1,200 V are interesting in applications such as
MOSFET devices that round out its Thanks to a very low on-state resistance solar converters, uninterruptible power sup-
650-V/1,200-V product portfolio. The tech- (R DS(on) ) dependency on temperature, the plies, battery chargers, and industrial drives.
nology is intended to complement not only MOSFETs feature excellent thermal behavior. The FS45MR12W1M1_B11 is an EasyPACK 1B
IGBTs in this blocking-voltage class but also The devices’ robust and stable body diodes are 1,200-V, 45-mΩ six-pack module with CoolSiC
the successful CoolMOS technology. CoolSiC said to retain a very low level of reverse- MOSFET, NTC resistor, and PressFIT contact
MOSFET 650-V devices are rated from 27 mΩ recovery charge (Q rr ) — roughly 80% lower technologies (Figure 2). It provides the high-
to 107 mΩ. They are available in the classic than that of the best superjunction CoolMOS est efficiency for reduced cooling effort with a
three-pin TO-247 package as well as the four- MOSFETs. The commutation robustness helps low-inductive design, according to Infineon.
pin version of the TO-247, which allows for in easily achieving overall system efficiency ROHM Semiconductor, for its part, offers the
even lower switching losses. Compared with of 98% — for example, through the usage of SCT3105KR 1,200-V SiC MOSFET, featuring

MARCH 2020 | www.eetimes.eu