the disruptive semiconductor technologies magazine - I-Micronews

OCTOBER 2010 issue n°100
THE DISRUPTIVE SEMICONDUCTOR TECHNOLOGIES MAGAZINE
POWER ELECTRONIC
Toyota, Daihatsu team up on light cars, EV/HEV business
Toyota Motor Corp and Daihatsu Motor Co Ltd announced that Daihatsu will supply its light cars to Toyota, which
will sell them under the Toyota brand in the Japanese market.
As the market for light cars is expanding, an
increasing number of Toyota customers are
willing to buy a light car, the companies said.
Daihatsu will supply the Move Conte and Hijet Cargo
light cars to Toyota from the fall of 2011 through the
end of 2011. And, in 2012, Daihatsu will supply another
type of passenger car to Toyota though the type of the
vehicle has not been determined yet.
"Though their Daihatsu logos will be replaced with
Toyota logos, they will have the same specifications,"
said Koichi Ina, president of Daihatsu. "We consider
it as OEM supply of existing vehicles. But, if they are
fully remodeled, we will supply the new models."
Toyota and Daihatsu have a contract called TAD
(Toyota Alliance with Daihatsu), under which their
outlet stores introduce their customers to each other.
The number of light cars sold at Toyota's outlet stores
under the contract is about 30,000 per year. In
consideration of the expanding light car market, Toyota
expects that the number will increase to 100,000 per
year in about 2012 (40,000 under the TAD contract
and 60,000 due to the OEM supply). Toyota will sell
the three types of vehicles supplied by Daihatsu at its
"Corolla" and "Netz" outlet stores across Japan. And,
in some areas where the ratio of light cars is high,
Toyota will also sell them at its "Toyota" and "Toyopet"
outlet stores. This time, Toyota and Daihatsu agreed
to collaborate on EVs and HEVs. Toyota will provide
EV/HEV technologies to Daihatsu, and Daihatsu will
consider releasing light EVs and HEVs. Daihatsu
plans to decide the kinds of technologies and the types
of light EVs and HEVs by the end of 2011.
www.toyota.co.jp
www.daihatsu.com
Toyota, Daihatsu team up on light cars, EV/HEV business
Power MOSFETs pack dual chips in small package
Renesas Electronics Corp. presents the RJK0222DNS and RJK0223DNS, two power semiconductor devices with
ultra-compact packages for use in DC/DC converters that provide power to the CPU, memory, and other circuit blocks
of products such as servers and notebook PCs.
The power semiconductor products each
integrate a pair of power MOSFETs into a
single package, enabling designs of DC/DC
converters that are more compact with higher
mounting density.
The compact, low-loss, 11th generation power
MOSFETs are contained in an ultra-compact package
measuring only 3.2mm × 4.8mm × 0.8mm (max.),
making it possible to reduce the mounting area by
about half compared with previous Renesas
Electronics power MOSFET products. At a switching
frequency of 300kHz, the power MOSFETs claim a
maximum efficiency of 95.2 per cent (input voltage:
12V, output voltage: 3.3V) which contributes to
improved overall power supply efficiency and reduced
power consumption. Within the pair of power
MOSFETs used for voltage conversion, the one used
for synchronous rectification (low-side) incorporates
an on-chip Schottky barrier diode. During the DC/DC
converter's dead time, the faster current switching
time from the power MOSFET to the Schottky barrier
diode reduces power loss. In addition, it effectively
suppresses the spike voltage when the power
MOSFET switches on, reducing the electromagnetic
noise. Like Renesas Electronics' existing WPAK
package, the HWSON3046 package offers heat
radiation and has a die pad on the bottom of the
device that allows heat to pass to the printed wiring
board while the power MOSFET is operating, enabling
the power MOSFET to handle large currents.
Renesas Electronics plans to develop a full line-up
of dual-chip products using the HWSON3046
package for a variety of DC/DC converter
specifications.
Samples of Renesas Electronics' power MOSFETs
are currently available. Mass production is scheduled
to begin in December 2010 and is expected to reach
a combined volume of 20 lakh units per month after
July 2011.
www.renesas.eu
Dual chips in small package
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Diamond-based SBD eliminates need for cooling
Japanese researchers made a Schottky barrier diode (SBD) by using diamond semiconductor.
When they checked the temperature
characteristics of the SBD, they found that
its current characteristics (when it is turned
off), etc do not have a temperature dependence
within a temperature range of 25-200°C.
This was announced by Osaka University and Japan's
National Institute of Advanced Industrial Science and
Technology (AIST) at the 71th Autumn Meeting 2010
of the Japan Society of Applied Physics, which took
place from Sept 14 to 17, 2010, in Japan.
The university and AIST made a SBD by combining
diamond semiconductor and Schottky electrodes
made by using ruthenium (Ru) and checked its
switching performance. As a result, they confirmed
that the SBD is capable of high-speed switching of
0.01μs and the recovery current dependent on the
rate of change (di/dt) of current and parasitic
inductance is as small as 40A/cm2. Therefore, the
loss of the SBD is low. The switching performance
did not change when the temperature was changed
between 25-200°C. So, the university and AIST
concluded that the SBD using diamond semiconductor
can potentially be applied to electric power conversion
systems that do not use a cooling system.
Some SiC-based power semiconductor chips stably
operate at temperatures higher than 200°. However,
in such high-temperature environments, it becomes
important to ensure the heat resistances of solder,
elemental devices (including packages), peripheral
circuits and so forth.
www.osaka-u.ac.jp
www.aist.go.jp
The diamond SBD
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