MAU400 Series
Test Configurations
Input Reflected-Ripple Current Test Setup
To Oscilloscope
+
Battery
+
Lin
Current
Probe
+Vin
+Out
Load
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 2.2uF for the 5V input devices, a 1.0uF for
the 12V input devices.
DC / DC
Converter
-Vin
-Out
Cin
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.
+
DC Power
Source
-
-Vin
+Vin
Single Output
DC / DC
Converter
-Out
+Out
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.
Peak-to-Peak Output Noise Measurement Test
Use a Cout 0.33uF ceramic capacitor.
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
Single Output
DC / DC
Converter
-Vin
-Out
+Out
Copper Strip
Cout
Scope
Resistive
Load
Cout
Load
+
DC Power
Source
-
+Vin
+Out
Dual Output
DC / DC Com.
Converter
Cout
Load
-Vin
-Out
+Vin
Dual Output
DC / DC
Converter
-Vin
+Out
Com.
Copper Strip
Cout
Cout
Scope
Resistive
Load
Scope
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 90°C.
The derating curves are determined from measurements
obtained in an experimental apparatus.
-Out
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.
For optimum performance we recommend 220
u
F
maximum capacitive load for dual outputs and 680
u
F
capacitive load for single outputs.
The maximum capacitance can be found in the data.
Position of air velocity
probe and thermocouple
15mm / 0.6in
50mm / 2in
Air Flow
DUT
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.
+
DC Power
Source
-
+
Cin
+Vin
DC / DC
Converter
-Vin
+Out
Load
-Out
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