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Figure 1.
Power comparison of Murata’s supercapacitors with various
battery technologies
making the capacitors short-circuit-
proof. Compared with a battery, the
supercaps only store about 10 Joules
of energy, which generates no stress
or significant heating effect on the part
even under short-circuit conditions.
Another feature of supercaps is
the virtually unlimited number of
charge and discharge cycles allowed
compared with finite numbers for
batteries. Lifetime is long, with
temperature and applied voltage
being accelerating factors. Under
controlled conditions, however, the
parts can easily give far more than five
years of useful service. Any concern
about moisture ingress is addressed
by the laminate construction, with
its minimal size of resin seal. Like
electrolytics, the temperature range
for supercaps is -40°C to +70°C or
+85 °C with similar ESR variation at
low temperatures.
Supercaps are polarized and available
up to about 5 V rating. In fact, the
typical DMT and DMF series from
Murata are already two ‘units’ in
series. Higher voltages can be easily
achieved with series connection of the
parts, with passive or active voltage
balancing schemes. Paralleling is
also easy with no special precautions
necessary to achieve more energy
storage. Charging is as quick as an
electrolytic capacitor from a simple
voltage source.
A significant benefit is the ultra-slim
form factor of the Murata DMT and
DMF series down to just
2.2 mm matching the demands of
today’s ‘pocketable’ and wearable
electronics.
Moving forward, portable devices will
become more multi-functional, smaller
and lighter. Supercapacitors from
Murata represent a complementary
and enabling technology.
Figure 2.
Supercapacitor packages
New-Tech Magazine Europe l 41