®
Test Configurations
Input Reflected-Ripple Current Test Setup
MDW1000 SERIES
DC/DC CONVERTER 2W,
DIP-Package
Input reflected-ripple current is measured with a inductor Lin (4.7uH) and Cin (220uF, ESR < 1.0Ω 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.
To Oscilloscope
+
Battery
+
Lin
Current
Probe
+Vin
+Out
Load
DC / DC
Converter
-Vin
-Out
Cin
Peak-to-Peak Output Noise Measurement Test
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.
+Vin
Single Output
DC / DC
Converter
-Vin
-Out
+Out
Copper Strip
Cout
Copper Strip
Resistive
Scope
Load
+Vin
Dual Output
DC / DC
Converter
-Vin
+Out
Com.
-Out
Copper Strip
Cout
Copper Strip
Cout
Copper Strip
Scope
Scope
Resistive
Load
Design & Feature Considerations
Maximum Capacitive Load
The MDW1000 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. The maximum capacitance can be found in the data sheet.
Overcurrent Protection
To provide protection in a fault (output overload) condition, the unit is equipped with internal current limiting circuitry and can endure current limiting for an unlimited
duration. At the point of current-limit inception, the unit shifts from voltage control to current control. The unit operates normally once the output current is brought back
into its specified range.
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 on the input to insure startup.
By using a good quality low Equivalent Series Resistance (ESR < 1.0Ω at 100 kHz) capacitor of a 8.2uF for the 5V input devices, a 3.3uF for the 12V input devices
and a 1.5uF for the 24V and 48V devices, capacitor mounted close to the power module helps ensure stability of the unit.
+
DC Power
Source
-
+
Cin
-Vin
-Out
+Vin
DC / DC
Converter
+Out
Load
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 3.3uF capacitors at the output.
+
DC Power
Source
-
-Vin
+Vin
Single Output
DC / DC
Converter
-Out
+Out
+
DC Power
Source
-
+Vin
+Out
Dual Output
DC / DC
Com.
Converter
Cout
Cout
Load
Load
Cout
Load
-Vin
-Out
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℃. The derating curves are determined
from measurements obtained in a test setup.
Position of air velocity
probe and thermocouple
15mm / 0.6in
50mm / 2in
Air Flow
DUT
18, Sin Sin Road, An-Ping Industrial District, Tainan 702, Taiwan
Tel: 886-6-2923150 Fax: 886-6-2923149 E-mail:
sales@minmax.com.tw
Minmax Technology Co., Ltd.
2011/08/11 REV:6
Page 4 of 4
MINMAX [ MINMAX TECHNOLOGY CO., LTD. ]
