EEV-FK0J471GP Datasheet, PDF (19/22 Pages) List of Unclassifed Manufacturers – Aluminum Electrolytic Capacitor

Electrolytic Capacitor Product Specification
Application Guidelines
CE-VFK-BE-33
17
1. Circuit Design
1.1 Operating Temperature and Frequency
Electrical parameters for electrolytic capacitors are normally specified at 20 ℃ temperature and 120 Hz frequency.
These parameters vary with changes in temperature and frequency. Circuit designers should take these changes into consideration.
(1) Effects of operating temperature on electrical parameters
a) At higher temperatures, leakage current and capacitance increase while equivalent series resistance (ESR) decreases.
b) At lower temperatures, leakage current and capacitance decrease while equivalent series resistance (ESR) increases.
(2) Effects of frequency on electrical parameters
a) At higher frequencies, capacitance and impedance decrease while tanδ increases.
b) At lower frequencies, heat generated by ripple current will rise due to an increase in equivalent series resistance (ESR).
1.2 Operating Temperature and Life Expectancy
(1) Expected life is affected by operating temperature. Generally, each 10 ℃ reduction in temperature will double the expected life.
Use capacitors at the lowest possible temperature below the upper category temperature.
(2) If operating temperatures exceed the upper category limit, rapid deterioration of electrical parameter will occur and
irreversible damage will result.
Check for the maximum capacitor operating temperatures including ambient temperature, internal capacitor temperature rise
due to ripple current, and the effects of radiated heat from power transistors, IC's or resistors.
Avoid placing components, which could conduct heat to the capacitor from the back side of the circuit board.
(3)　The formula for calculating expected life at lower operating temperatures is as follows ;
Ｔ１ーＴ２
Ｌ２ = Ｌ１× ２ ^１０
L₁ : Guaranteed life (h) at temperature, T₁℃
L₂ : Expected life (h) at temperature, T₂℃
T₁ : Upper category temperature (℃)
T₂ : Actual operating temperature, ambient temperature + temperature rise due to ripple current heating(℃)
1.3 Common Application Conditions to Avoid
The following misapplication load conditions will cause rapid deterioration of a capacitor’s electrical parameters.
In addition, rapid heating and gas generation within the capacitor can occur, causing the pressure relief vent to operate and
resultant leakage of electrolyte. Under extreme conditions, explosion and fire ignition could result.
The leaked electrolyte is combustible and electrically conductive.
(1) Reverse Voltage
DC capacitors have polarity. Verify correct polarity before insertion. For circuits with changing or uncertain
polarity, use DC bipolar capacitors. DC bipolar capacitors are not suitable for use in AC circuits.
(2) Charge / Discharge Applications
Standard capacitors are not suitable for use in repeating charge/discharge applications. For charge/discharge
applications, consult us with your actual application condition.
(3) Over voltage
Do not apply voltages exceeding the maximum specified rated voltage. Voltages up to the surge voltage rating are acceptable
for short periods of time. Ensure that the sum of the DC voltage and the superimposed AC ripple voltage does not exceed
the rated voltage.
(4) Ripple Current
Do not apply ripple currents exceeding the maximum specified value. For high ripple current applications, use a capacitor
designed for high ripple currents. In addition, consult us if the applied ripple current is to be higher than the maximum specified
value. Ensure that rated ripple currents that superimposed on low DC bias voltages do not cause reverse voltage conditions.
1.4 Using Two or More Capacitors in Series or Parallel
(1) Capacitors Connected in Parallel
The circuit resistance can closely approximate the series resistance of the capacitor, causing an imbalance of ripple current loads
within the capacitors. Careful wiring methods can minimize the possible application of an excessive ripple current to a
capacitor.
(2) Capacitors Connected in Series
Differences in normal DC leakage current among capacitors can cause voltage imbalances. The use of voltage divider
shunt resistors with consideration to leakage currents can prevent capacitor voltage imbalances.
Matsushita Electronic Components Co.,Ltd.　LCR Device Company
Capacitor Business Unit