MKW5000 Series
Input Source Impedance
The power module should be connected to a low
ac-impedance input source. Highly inductive source
impedances can affect the stability of the power module.
In applications where power is supplied over long lines and
output loading is high, it may be necessary to use a capacitor
at the input to ensure startup.
Capacitor mounted close to the power module helps
ensure stability of the unit, it is recommended to use a good
quality low Equivalent Series Resistance (ESR < 1.0[ at 100
KHz) capacitor of a 33uF for the 12V input devices and a 10uF
for the 24V and 48V devices.
+
DC Power
Source
-
+
Cin
-Vin
-Out
+Vin
DC / DC
Converter
+Out
Load
Thermal Considerations
Many conditions affect the thermal performance of the
power module, such as orientation, airflow over the module
and board spacing. To avoid exceeding the maximum
temperature rating of the components inside the power
module, the case temperature must be kept below 105°C.
The derating curves are determined from measurements
obtained in an experimental apparatus.
Position of air velocity
probe and thermocouple
15mm / 0.6in
50mm / 2in
Air Flow
DUT
Output Ripple Reduction
A good quality low ESR capacitor placed as close as
practicable across the load will give the best ripple and noise
performance.
To reduce output ripple, it is recommended to use 4.7uF
capacitors at the output.
+
DC Power
Source
-
-Vin
+Vin
Single Output
DC / DC
Converter
-Out
+Out
.
Cout
Load
Maximum Capacitive Load
The MKW5000 series has limitation of maximum
connected capacitance at the output.
The power module may be operated in current limiting
mode during start-up, affecting the ramp-up and the startup
time.
For optimum performance we recommend 680uF
maximum capacitive load for 12V & 15V outputs and 6800uF
capacitive load for the other outputs.
The maximum capacitance can be found in the data sheet.
7
MINMAX
REV:0 2005/04