MIHW3000 Series
Input Source Impedance
Test Configurations
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
on the input to insure startup.
Input Reflected-Ripple Current Test Setup
Input reflected-ripple current is measured with a inductor
Lin (4.7uH) and Cin (220uF, ESR < 1.0[ at 100 kHz) to
simulated source impedance.
Capacitor Cin, offsets possible battery impedance.
Current ripple is measured at the input terminals of the
module, measurement bandwidth is 0-500KHz.
By using a good quality low Equivalent Series Resistance
(ESR < 1.0[ at 100 kHz) capacitor of a 10uF for the 12V input
devices and a 4.7uF for the 24V input devices and a 2.2uF for
the 48V devices, capacitor mounted close to the power
module helps ensure stability of the unit.
To Oscilloscope
+Vin
+Out
+
+
Lin
DC / DC
Converter
Current
Probe
Load
Battery
Cin
-Vin
-Out
+
+Vin
DC / DC
+Out
-Out
+
DC Power
Source
Load
Converter
Cin
Peak-to-Peak Output Noise Measurement Test
-
-Vin
Use a Cout 0.47uF 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.
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 that 3.3uF
capacitors are used on output.
+Vin
+Out
Copper Strip
Cout
Single Output
DC / DC
Resistive
Load
Scope
Converter
-Vin
-Out
Copper Strip
+
+Vin
+Out
Single Output
DC / DC
DC Power
Source
Copper Strip
Cout
+Vin
+Out
Com.
-Out
Converter
Cout
Load
Scope
Scope
Dual Output
DC / DC
-
-Vin
-Out
Resistive
Load
Copper Strip
Cout
Converter
-Vin
Copper Strip
+
+Vin
+Out
Load
Load
Dual Output
Cout
Cout
DC Power
Source
DC / DC
Com.
-Out
Converter
Design & Feature Considerations
Maximum Capacitive Load
-
-Vin
The MIHW3000 series has limitation of maximum
connected capacitance on the output.
The power module may operate in current limiting mode
during start-up, affecting the ramp-up and the startup time.
Connect capacitors at the point of load for best
performance.
The maximum capacitance can be found in the data sheet.
REV:5 2009/02/02
MINMAX
6
MINMAX [ MINMAX TECHNOLOGY CO., LTD. ]
