MAU400 Series
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.
Test Configurations
Input Reflected-Ripple Current Test Setup
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 2.2uF for the 5V input devices, a 1.0uF for
the 12V input devices.
To Oscilloscope
+Vin
+Out
+
+
Lin
DC / DC
Converter
Current
Probe
Load
Battery
Cin
-Vin
-Out
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 1.5uF
capacitors at the output.
Input reflected-ripple current is measured with a inductor
Lin (4.7uH) and Cin (220uF, ESR < 1.0[ at 100 KHz) to
simulate source impedance.
Capacitor Cin, offsets possible battery impedance.
Current ripple is measured at the input terminals of the
module, measurement bandwidth is 0-500 KHz.
+
+Vin
+Out
Peak-to-Peak Output Noise Measurement Test
Single Output
DC / DC
DC Power
Source
Use a Cout 0.33uF ceramic capacitor.
Converter
Cout
Load
Scope measurement should be made by using a BNC
socket, measurement bandwidth is 0-20 MHz. Position the
load between 50 mm and 75 mm from the DC/DC Converter.
-
-Vin
-Out
+Vin
+Out
Copper Strip
Cout
+
+Vin
+Out
Single Output
DC / DC
Dual Output
Resistive
Load
Cout
Load
DC Power
Source
Scope
DC / DC Com.
Converter
Converter
-Vin
-Out
-
-Vin
-Out
Copper Strip
Cout
+Vin
+Out
Com.
-Out
Thermal Considerations
Scope
Scope
Dual Output
DC / DC
Resistive
Load
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 90°C.
The derating curves are determined from measurements
obtained in an experimental apparatus.
Converter
Cout
-Vin
Design & Feature Considerations
Maximum Capacitive Load
The MAU400 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.
Position of air velocity
Air Flow
50mm / 2in
probe and thermocouple
15mm / 0.6in
DUT
For optimum performance we recommend 220uF
maximum capacitive load for dual outputs and 680uF
capacitive load for single outputs.
The maximum capacitance can be found in the data.
+
+Vin
DC / DC
+Out
-Out
Input Source Impedance
+
DC Power
Source
Load
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.
Converter
Cin
-
-Vin
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