Maxcap® double layer capacitors are a new electric energy storage device with extremely high volumetric efficiency (over five farads/in3), virtually unlimited service life, fast charge/discharge capability and very low leakage current. A Maxcap DLC the size of thimble will support microamp data retention currents of CMOS RAMs for up to several weeks, Microprocessors, small motors and activators having current requirements from one to several hundred milliamps can be supported from several seconds to minutes. Conventional energy storage devices such as batteries and aluminum electrolytic capacitors often must be replaced during the life of a product. Maxcap DLCs never need replacing because, unlike batteries, they do not undergo life-limiting, irreversible, chemical reactions, and, unlike aluminum electrolytic capacitors, they do not experience dry-up problems. The high capacitance of Maxcap DLCs results from an electric double layer formed at the interface of high surface area activated carbon and a stable electrolyte. Unit cells are formed by separating two carbon/electrolyte wafers with an ionically conductive porous separator and sandwiching them between two electrically conductive, ionically impermeable membranes. The unit cells are stacked in series to achieve the desired capacitor voltage. CAUTION: Due to their relatively high internal resistance, Maxcap DLCs should not be subjected to large ripple currents
Applications
- CMOS; RAMS and microprocessors, Timers for Integrated Cicuits: Home appliances such as TVs, microwave ovens, dishwashers, and refrigerators; utility meters, personal computers, energy management controls, thermostats, point of sale terminals, process controllers, routers.
- Relays, Solenoids: Starters, igniters, actuators
- Small Motors, Alarms: Disc drives, coin metering devices, security systems, toys.
- Data Transmission: Vehicle tracking systems, utility meters.
Features
- High Energy Density Capacitors for Memory Backup and Data Transmission Power
- New LM Surface Mount Product Series
- Very high capacity in small size: Up to 100 times that of conventional capacitors
- Useful voltage ratings: 3.5 and 5.5 volt – Ideal for CMOS operating voltage range. 11 volt – LV Series, backup for relays, actuators, small motors
- Full range of sizes: From 0.01 to 5.6 farads @ 5.5 volts; 0.47, 1.0 and 5.0 farads @ 11 volts.
- Low profile with LP, LJ and LK Series
- Ultra long life: Unlike batteries, Maxcap DLCs have no parasitic chemical reactions. They can be fully charged and discharged indefinitely. There is no “memory” effect.
- One Farad in a 0.65"x 0.75" Package
- Up to 5.6 Farads in a 5.5 Volt Package
- Up to 5.0 Farads in an 11.0 Volt Package
Specifications
- Very low ESR: As low as 0.3, typica
- As low as 0.3, typical For short time, high current (up to amps)
- High energy density: One farad in 1.44" x 0.73" package
- Up to 1.5 farads in single package
- Typ.** Long Charge Leakage Current: 1–25μa
- Operating temp.: -25˚C to +70˚C
- Storage temp: -40˚C to +85˚C
- Reduced diameter, high energy density, low leakage current
- Several weeks (microamps)
- Small diameter
- Very high energy density One farad in 0.85" x 0.63" Up to 2.2 farads in single package
- Low self discharge rate
- Typ.** Long Charge Leakage Current: 0.1–6μa
- Operating temp.: -25°C to +70°C
- Storage temp.: -40°C to +85°C
- Reduced height, high energy density, low leakage current
- Several weeks (microamps)
- Low profile
- Very high energy density One farad in 1.12" x 0.44" package
- Low self discharge rate
- Typ.** Long Charge Leakage Current: 0.1–4μa
- Operating temp.: -25°C to +70°C
- Storage temp.: -40°C to +85°C
- Expanded temperature range, low leakage current
- Several weeks (microamps)
- Expanded temperature range (Oper.: -40°C to +85°C; Storage: -40°C to +85°C)
- High energy density One farad in 0.85" x 0.87" package
- Typ.** Long Charge Leakage Current: 0.1–4μa
- Very low ESR
- For short time, high current (up to amps)
- Very low ESR As low as 0.3, typical
- High energy density One farad in 1.44" x 0.73" package Up to 1.5 farads in single package
- Typical** Long Charge Leakage Current: 1–25μa
- Operating temp.: -25°C to +70°C
- Storage temp.: -40°C to +85°C
- Increased voltage capability, low ESR
- For short time, high current, high voltage (up to milliamps)
- 11 volts rating Up to 5 farads in single package
- Low ESR
- Typ.** Long Charge Leakage Current: 1–4μa
- Operating temp.: -25°C to +70°C
- Storage temp.: -40°C to -85°C
- Our highest energy density product, low self discharge rate
- Several weeks (microamps)
- Our Highest Energy Density Product One farad in 0.65" x 0.75" package Up to 4.7 farads in a single package
- Small Diameter
- Low self discharge rate
- Typical** Long Charge Leakage Current:
- Operating temp.: -25°C to +70°C
- Storage temp.: -40°C to +85°C
- Expanded temperature range
- Low ESR
- Several weeks (microamps); For short time (milliamps)
- Expanded temperature range (Oper.: -40°C to +85°C; Storage: -40°C to +85°C)
- Very high energy density with low ESR One farad in 0.85" D x 0.51" H package Up to 5.6 farads in a single package
- Low profile
- Low self discharge rate
- Typ.** Long Charge Leakage Current: 0.7–15μa
- Surface mount design, low self discharge
- Several weeks (microamps)
- Surface Mount Design
- One Farad in 0.85" x 0.85" x 0.41" package
- Low self discharge rate
- 5.5V (LM055) or 3.5V (LM035)
- Typ.** Long Charge Leakage Current: 0.5–10μa
- Operating temp.: -25°C to +70°C
* For indication of long term charging current (typical leakage current), see pages XXX.
**Charging current after 72 hours with 1000Ω resistor in series with capacitor at 25°C, see pages XXX.
Characteristics
LM Surface Mount Products
**% of values in product tables ***% of initial measured value
LM Surface Mount Products
**% of values in product tables ***% of initial measured value
LM Surface Mount Solder Reflow Recommendations
The LM Series capacitor is designed for use in Infrared or Vapor Phase Convection solder reflow processes. The chart at right indicates typical time-temperature conditions for these processes. Recognizing that a wide range of time and temperature conditions is possible depending on each manufacturer’s circumstances, it is recommended that manufacturers adhere to the following general process guideline: MaxCap DLC peak temperature at the top surface of the capacitor should be limited to 235°C for less than 10 seconds.
Adherence to this guideline should enable successfulprocessing and allow for normal variation in time and temperature for most customer processes. Please consult the factory with questions regarding your specific process conditions
Typical Solder Reflow Time – Temperature Profile
Dimensions
inches (mm)
Land Pattern
Electrical Characteristic Measurement Methonds
1. Capacitance Charge Method
Capacitance in farads can be calculated by using the formula
and charging test circuit in the figure:
a. Test temperature – Capacitors to be at +25˚ ±5˚C.
b. Initial capacitor voltage to be less than 0.05V.
c. Vc = Volt meter (DC).
d. E0 = 5.0 + 0.1V for LC, LF, LK, LP, LT, LX, LJ Series; LV
Series: 10.0 + 0.1V for 11 V Rating. 12.0 + 0.1V for 12 V
Rating.
e. T = Charging time constant, that is, the time period in seconds from 0 to reach 0.632 x E0 volts.
f. Rc = Charging resistor selected from the table.
2. Discharge Method LM Series – 5.5V & 3.5V Products
Capacitance in farads is calculated by using the formula and
discharging test circuit in the Figure:
a. Test temperature – Capacitors to be at +25˚ ±5˚C.
b. Vc = Volt meter (DC).
c. E0 = 5.5V or 3.5V; I = Current (amps);
T = Time (seconds)
d. AL = Constant Current Load Device
e. Initial capacitor voltage to be less than 0.05V.
f. Begin charging capacitor to rated voltage (5.5V OR 3.5V).
When the capacitor terminal voltage reaches the rated voltage, continue charging for another 30 minutes. 1.0F capacitors
should be charged for 60 minutes.
g. Discharge the capacitor with AL (Constant Current Load
Device) at a load of 1.0ma per 1.0 Farad. For example, a 0.47F
capacitor will be discharged at a current of 0.47ma.
h. Measure the time for the terminal voltage to fall from 3.0V to
2.5V for the 5.5V rated products
and from 1.8V to 1.5V for the 3.5V rated products.
i. Calculate capacitance in farads using the equation
in Figure 3.
3. Equivalent Series Resistance (ESR)
ESR in ohms can be measured using the test circuit the figure:
a. Test temperature and tolerance – Capacitor to be at +25˚C
±5˚C.
b. Test frequency – 1,000 ±100 Hz.
c. The magnitude of the AC voltage to be limited to 0.5 volt
rms maximum.
d. A = Ampere meter (AC).
e. Vc = Volt meter (AC)
Note: Volt meter impedance to be significantly higher than that
of the capacitor.
4. DC Leakage Current (Charging Current – 30 Minute)
DC leakage current or charging current is measured using the
test circuit and procedure in the figure:
a. Test temperature and tolerance – Capacitors to be at +25˚C
±5˚C.
b. Initial capacitor voltage to be less than 0.05V.
c. Vc – Volt meter (DC).
d. E0 = Same voltage as used in capacitance
measurement method.
e. VR = Voltage drop by resistance Rc after 30 minutes on
charge.
f. Rc = Charging resistors selected from the table below:
0.01 – 0.047F 1000Ω
0.1 – 0.47F 100Ω
1.0 – 5.6F 10Ω
LV Series:
0.47 & 1.0F 100Ω
5.0F 10Ω
Minimum Backup Time Capability
These curves indicate the discharge times for Maxcap DLCs
through constant resistance loads after charging for 24 hours
at 5.0 volts. They show minimum backup time for a voltage
range of from 5 to 2 volts, the typical data retention range for
CMOS RAMs
The actual backup time will be longer than indicated because
the current draw of CMOS RAMs over the data retention voltage is somewhat less than that of constant resistance loads
even though the initial current is the same.
Back Up Times
Backup times at 25°C for constant resistance loads. Voltage versus backup time for a number of constant resistance loads for LC, LK, LT and LV Series capacitors after charging for 24 hours at 5.0 or 10 volts.
Chrarging Characteristics
Maxcap DLCs can be charged to their working voltage in a matter of seconds. Typical charge time versus voltage and current curves are given in the graph for Maxcap DLC LP055104A
Self Discharge Curves
Graph shows self discharge curves (open circuit) for LC, LK and LT Series capacitors after charging for 24 hours at 5.0 volts.
Long Term Charging Curves
These graphs show typical long term charging curves for each of the Maxcap DLC Capacitor Series using the circuit shown at right.
Electrical Characteristics Versus Temperatures
Graphs show typical changes in capacitance and ESR over the temperature range from –55 to +85˚C. Note that the rated operating temperature for LP, LV, LC, LK, LX and LF Series capacitors is -25 to +70˚C; LT & LJ- Series, -40 to +85˚C.
Ordering Information
