MKP385e

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Vishay BCcomponents

Revision: 28-May-2019

21

Document Number: 28255

THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT

APPLICATION NOTES

For capacitors connected in parallel, normally the proof voltage and possibly the rated voltage must be reduced. For information

These capacitors are not suitable for mains applications as across-the-line capacitors without additional protection, as

described hereunder. These mains applications are strictly regulated in safety standards and therefore electromagnetic

interference suppression capacitors conforming the standards must be used.

To select the capacitor for a certain application, the following conditions must be checked:

3. The voltage peak slope (dU/dt) shall not exceed the rated voltage pulse slope in an RC-circuit at rated voltage and without

divided by the applied voltage.



For all other pulses following equation must be fulfilled:











T is the pulse duration

4. The maximum component surface temperature rise must be lower than the limits (see graph “Max. allowed component

temperature rise”)

5. Since in circuits used at voltages over 280 V peak-to-peak the risk for an intrinsically active flammability after a capacitor

breakdown (short circuit) increases, it is recommended that the power to the component is limited to 100 times the values

mentioned in the table: “Heat Conductivity”

6. When using these capacitors as across-the-line capacitor in the input filter for mains applications or as series connected

with an impedance to the mains the applicant must guarantee that the following conditions are fulfilled in any case (spikes

and surge voltages from the mains included)



Note



• See table “Voltage Ratings and Temperature”

7. For capacitors with multiple pins in some cases it is allowed to feed current through the pins additionally to the capacitor to

improve filtering properties

2

dU

dt

--------





2

0

T



dt

U

RDC

dU

dt

--------





rated









P

2

I

2

P

2

P

1

I

1

I

I

1

I