DC-2R5D204T614 Elna America, DC-2R5D204T614 Datasheet - Page 139

• Manufacturer Part Number: DC-2R5D204T614
• Description: CAP DOUBLE LAYER .20F 2.5V COIN
• Manufacturer: Elna America
• Series: DCr

Specifications of DC-2R5D204T614

• Capacitance: 200mF
• Voltage - Rated: 2.5V
• Tolerance: -20%, +80%
• Esr (equivalent Series Resistance): 100.00 Ohm
• Lifetime @ Temp.: 1000 Hrs @ 70°C
• Mounting Type: Surface Mount
• Package / Case: Surface Mount - Coin Style
• Height: 0.083" (2.10mm)
• Size / Dimension: 0.268" Dia (6.80mm)
• Operating Temperature: -25°C ~ 70°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Spacing: -
• Other names: 604-1075

CAT.No.2008/2009E ( 2008.10.1 )
1 Description of Electric Double Layer
1-1 Basic Concepts
Generally capacitors are constructed with a dielectric
placed between opposed electrodes, functioning as
capacitors by accumulating charges in the dielectric
material. Aluminum electrolytic and tantalum electro-
lytic capacitors, for example, use an aluminum oxide
film and a tantalum oxide film as the dielectric,
respectively.
On the other hand, Electric Double Layer Capacitors
have no visible dielectric in a general sense but utilize
the state referred to as the electric double layer, which
is developed naturally on the interface between
substances, as the function of dielectric.
1-2 Operating Principle
The Electric Double Layer represents the state in
which positive and negative charges exist at a very
short distance on the boundary where contact occurs
between two different substances (e.g. solid and
liquid). By externally applying a voltage below a
certain voltage to the boundary, higher charges can
be accumulated. Accordingly, charge and discharge
of electric double layer capacitors utilize adsorption
and desorption of ions to the ionic adsorption layer
(Electric Double Layer) formed on the electrode
surface of the activated carbon used for electrodes.
TECHNICAL NOTE
Fig.1 Schematic of Principle of Electric Double Layer Capacitor
Capacitor
Activated
carbon
Charge
Electrolyte
Discharge
Activated
carbon
ELECTRIC DOUBLE
LAYER CAPACITORS
Applying DC voltage externally across the electrodes
of the Electric Double Layer allows almost no passage
of current up to a certain voltage, exhibiting a
condition like insulation.
However, the application of voltages exceeding the
certain voltage causes electrolysis to occur in the
electrolyte, resulting in abrupt passage of current.
This voltage determines the resistance of voltage of
an Electric Double Layer Capacitor. We use an
organic electrolyte and its standard electrolysis occurs
at the voltage of about 2.5∼3V.
1-3 Advantages and Disadvantages of Electric
Double Layer Capacitor
[Advantages]
(1) Small size and capacitance in farads ( F ) available
(1)
(2) No special charging circuit and constrains during
(3) No effect on the life through overcharging and
(4) Environmentally clean energy
[Disadvantage]
(1) The life is limited due to the use of electrolyte.
(2) Series connection is required when used with a
(3) Cannot be used in AC circuits due to high internal
by utilizing the activated carbon electrode with a
large surface area
discharge are required.
overdischarging
low resistance of voltage at a high voltage.
resistance unlike aluminum electrolytic capacitors.
NOTE
Design, Specifications are subject to change without notice.
Ask factory for technical specifications before purchase and/or use.
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