MKP1848 DC-Link
www.vishay.com
Vishay Roederstein
Revision: 24-Mar-17
15
Document Number: 28164
For technical questions, contact: dc-film@vishay.com
THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. THE PRODUCTS DESCRIBED HEREIN AND THIS DOCUMENT
ARE SUBJECT TO SPECIFIC DISCLAIMERS, SET FORTH AT www.vishay.com/doc?91000
POWER DISSIPATION AND MAXIMUM COMPONENT TEMPERATURE RISE
The power dissipation must be limited in order not to exceed the maximum allowed component temperature rise as a function
of the free air ambient temperature.
The component temperature rise (T) can be measured or calculated by T = P/G:
• T = T
C
- T
amb
= case temperature rise (°C) with a maximum of 15 °C at rated temperature.
• P = I
RMS
2
x ESR = power dissipation of the component (mW)
• G = heat conductivity of the component (mW/°C)
MEASURING THE COMPONENT TEMPERATURE
The case temperature is measured in unloaded (T
amb
) and maximum loaded condition (T
C
).
To avoid thermal radiation or convection, the capacitor must be tested in a closed area from air circulation.
APPLICATION NOTE AND LIMITING CONDITIONS
These capacitors are not suitable for mains applications as across-the-line capacitors without additional protection.
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:
• The continuous peak voltage (U
P+
) shall not exceed the rated DC voltage rating (U
NDC
)
• The peak-to-peak ripple voltage (U
PP
) shall not be greater than 0.2 x (U
NDC
)
• For capacitors connected in parallel, normally the proof voltage and possibly the rated voltage must be reduced. For
information depending of the capacitance value and the number of parallel connections contact: dc-film@vishay.com
• The voltage peak slope (dU/dt) shall not exceed the pulse slope at the DC voltage rating.
If the pulse voltage is lower than the rated DC voltage, the rated voltage pulse slope may be multiplied by U
NDC
and divided
by the applied voltage.
For all other pulses following equation must be fulfilled:
T is the pulse duration
Maximum Repetitive Peak Voltages
The capacitor unit may be subjected to the following surge without any significant reduction of lifetime expectancy
REPETITIVE SURGE VOLTAGE MAXIMUM DURATION PER DAY
1.1 x U
NDC
30 % on load duration
1.15 x U
NDC
30 min
1.2 x U
NDC
5 min
1.3 x U
NDC
1 min
1.5 x U
NDC
110 ms
U
p+
U
NDC
U
p-
Voltage (V)
t
Non reversing recurrent waveform
2 x
dU
dt
-------
2
x dt U
NDC
x
dU
dt
-------
rated
0
T
