EDLF684B5R5C Cornell-Dubilier, EDLF684B5R5C Datasheet - Page 6

• Manufacturer Part Number: EDLF684B5R5C
• Description: CAPACITOR, ALUMINUM ELECTRONIC (EDL) STACKED COIN, .68 F, 5.5 VOLT, MAX RES. 50
• Manufacturer: Cornell-Dubilier

Specifications of EDLF684B5R5C

• Capacitance: 0.68 F
• Material, Element: Electric Double Layer
• Special Features: Supercapacitors and Ultracapacitors
• Termination: Stacked Coin
• Voltage, Rating: 5.5 VDC
• Capacitance Range: .22 F to 70 F
• Temperature Range: -25 C to + 85 C
• Case Types: Radial Leaded, Stacked Coin, SMT
• Lead Free Status / Rohs Status: RoHS Compliant part

How to Select an Electric Double Layer Supercapacitor
Estimated initial back-up time
Back-up time for Type EDL Electric Double Layer Supercapacitors decreases with use and over time
especially when the current is large or operating at high temperature. Be sure to specify extra back-up
time initially to allow for product changes.
Select the optimum supercapacitor according to applied current.
The internal resistance of the supercapacitor prevents drawing high discharge currents. Select the
supercapacitor capable of delivering the peak current at switchover to back-up mode using the follow-
ing table.
Back-up Time Example
Back-up time is the time it takes for the applied voltage to decay to the cut-off voltage set by the user
after applying the application’s maximum voltage at application maximum temperature.
Example: An F Type EDL, P/N EDLF105B5R5C (Rated at 5.5 V, 1.0 F) is charged to 5.0 Vdc. The circuit
requirement is such that it must maintain a memory circuit with a current drain of 10 µA in an ambient
temperature of +40 ºC. The memory RTC cut-off voltage is 2.0 Vdc.
Using minimum capacitance, calculate the back-up time as
follows:
t = CΔV ⁄ I = C[V
C = 1.0 F–20% = 0.8 F, R=50 Ω, V
Therefore,
t = 0.8 (5–0.0005–2) ⁄ (10+2) ⁄ 10
And thus the initial back-up time is 55 hours. After 1000 hours,
Life Design for Electric Double Layer Supercapacitors
Type EDL supercapacitors have a useful lifetime that decreases with increasing operating temperature,
humidity, applied-voltage, current and backup-time requirements.
Expected lifetime is the product of four factors:
CDE Cornell Dubilier • 1605 E. Rodney French Blvd. • New Bedford, MA 02744 • Phone: [phone] • Fax: [phone] • www.cde.com
SG, SD, NF
Expected Life = (Lifetime)•(Temperature Factor)•(Voltage Factor)•(Moisture Factor)
Series
HW
EN
F
0
–(i
•
R)–V
0.047 F
200 µA
200 µA
1
] ⁄ (i+i
–
–
L
)
–6
0
= 55 hours
=5 V. V
0.1 F to 0.33 F
300 µA
300 µA
10 µA
–
1
Maximum Operating (Discharge) Current
=2 V, i=10 µA
0.47 F to 1.5 F
100 mA
300 µA
1 mA
–
t: Back-up time (s)
C: Capacitance of Type EDL (F)
V
V
i: Current during back-up (A)
i
R: Internal resistance (Ω) at 1 kHz
L
: Leakage current (A)
0
1
: Applied voltage (V)
: Cut-off voltage (V)
3.3 F to 4.7 F
300 mA
–
–
–
10 F to 50 F
1 A
–
–
–