Type EDL , Electric Double Layer Supercapacitors Ultra High Capacitance, Small Case Size Options Type EDL electric double layer supercapacitors offer extremely high capacitance values (farads) in a variety of packaging options that will satisfy, low profile, surface mount, through hole and high density assembly requirements. The EDL is a cut above the standard electrolytic capacitor in that it can act as a battery without having to deal with the environmental or hazardous material issues that batteries entail. Highlights - Unlimited charging and discharging capability - Recycling is not necessary - Long Life - 15 years - Low ESR - Will extend battery life up to 1.6 times - First class performance with economy pricing Specifications Operating Temperature Range 25 C to +85 C Rated Voltage Range 2.1 Vdc to 5.5 Vdc Capacitance Range 0.022 F to 70 F How To Select an Electric Double Layer Capacitor Estimated Initial Backup Time Back-up time for Type EDL Electric Double Layer Supercapacitors decreas- es with use and over time especially when the current is large or operat- ing at high temperature. Be sure to specify extra back-up time initially to allow for product changes. Select the optimum supercapacitor according to applied The internal resistance of the supercapacitor prevents drawing high current discharge currents. Select the supercapacitor capable of delivering the peak current at switchover to back-up mode using the following table. Maximum Operating (Discharge) Current Series 0.1 F to 0.47 F to 3.3 F to 10 F to 0.047 F 0.33 F 1.5 F 4.7 F 50 F SG, SD, NF 200 A 300 A 1 mA F 200 A 300 A 300 A EN 10 A HW 300 mA 1 A 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 applications 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 A in an ambient temperature of +40 C. The memory RTC cut-off voltage is 2.0 Vdc. Using minimum capacitance, calculate the back-up time as follows: t = CV I = C V0(iR)V1 (i+iL) C = 1.0 F20% = 0.8 F, R=50 , V0=5 V, V1=2 V, i=10 A Therefore, t = 0.8 (50.00052) ((10+2) x10 6)= 55 hours And thus the initial back-up time is 55 hours. After 1000 hours, calculate the back-up time will drop to about 38 hours. t: Back-up time (s) C: Capacitance of Type EDL (F) V : Applied voltage (V) 0 V : Cut-off voltage (V) 1 i: Current during back-up (A) i : Leakage current (A) L R: Internal resistance () at 1 kHz CDE Cornell Dubilier 1605 E. Rodney French Blvd. New Bedford, MA 02744 Phone: (508)996-8561 Fax: (508)996-3830 Type EDL , Electric Double Layer Supercapacitors Ultra High Capacitance, Small Case Size Options Life Design 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: Expected Life = (Lifetime)(Temperature Factor)(Voltage Factor)(Moisture Factor) Lifetime The minimum rated life at 85 C with 5.5 Vdc applied is 1000 hours with maximum permitted end-of-life capacitance change of 30% and a 4 times increase in internal resistance. Temperature Factor To determine the effect of temperature on expected life of a supercapaci- tor, use the fact that expected lifetime doubles for each 10 C that the operating temperature is reduced. As an illustration, at 85 C and full voltage the rated lifetime is 1000 hours. So, at 40 C the expected lifetime would be multiplied by 2(85-40)/10 = 2 4.5 = 22.6 times. The Tempera- ture Factor is 22.6, and for 1000-h, 85 C rated life, the expected 40 C life would be 22600 hours. Voltage Factor The rate of change of capacitance decreases with decreasing applied voltage. The effect on life extension is roughly proportional to the voltage derating, e.g., 5 V applied to 5.5 V rated supercapacitors extends the life 1.1 times. Moisture Factor Expected life of these supercapacitors is considerably shortened by operation in high humidity. The applications discussed here assume that the relative humidity is no more than 50%. Expected Life Example So, for a 5.5 V supercapacitor at 40 C charged to 5.V in less than 50% RH the expected life is: Expected Life = (Lifetime) (Temperature Factor) (Voltage Factor) (Moisture Factor) = (1000 h) (22.6) (1.1) (1) = 24800 hours = 2.8 years RoHS Compliant Electric Double Layer Supercapacitor Construction Current Current Activated Collector Electrolyte Separator Collector Carbon Resistor Resistor Electric Double to Charge to Move Ions Layer Capacitor CDE Cornell Dubilier 1605 E. Rodney French Blvd. New Bedford, MA 02744 Phone: (508)996-8561 Fax: (508)996-3830