MJWI10 SERIES
DC/DC CONVERTER 10W, High Power Density
Total Power International, Inc.
Test Setup
Input Reflected-Ripple Current Test Setup
Input reflected-ripple current is measured with a inductor Lin (4.7μH) and Cin (220μF, 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
+Vin
+Out
+
+
Lin
DC / DC
Converter
Current
Probe
Load
Battery
Cin
-Vin
-Out
Peak-to-Peak Output Noise Measurement Test
Use a Cout 0.47μF 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.
Copper Strip
Cout
+Vin
+Out
Copper Strip
Cout
+Vin
+Out
Com.
-Out
Scope
Scope
Single Output
DC / DC
Converter
Dual Output
DC / DC
Converter
Resistive
Load
Resistive
Load
Scope
Copper Strip
Cout
-Vin
-Out
Copper Strip
-Vin
Copper Strip
Technical Notes
Remote On/Off
Positive logic remote on/off turns the module on during a logic high voltage on the remote on/off pin, and off during a logic low. To turn the power module on and off,
the user must supply a switch to control the voltage between the on/off terminal and the -Vin terminal.
The switch can be an open collector or equivalent. A logic low is 0V to 1V. A logic high is 2.5V to 50V. The maximum sink current at on/off terminal during a logic
low is -500μA. The maximum allowable leakage current of the switch at on/off terminal (2.5 to 50V) is 500μA.
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 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 <
1.0Ω at 100 KHz) capacitor of a 6.8μF for the 24V and 48V devices.
+
+Vin
+Out
+
DC / DC
Converter
DC Power
Source
Load
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 4.7μF capacitors at the output.
+
+Vin
-Vin
+Out
+
+Vin
-Vin
+Out
Com.
-Out
Single Output
DC / DC
Converter
Load
Load
Dual Output
DC / DC
Converter
DC Power
Source
Cout
Cout
DC Power
Source
Cout
Load
-
-Out
-
Maximum Capacitive Load
The MJWI10 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. The maximum capacitance can be found in the data sheet.
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 100℃. The derating curves are determined
from measurements obtained in a test setup.
Position of air velocity
probe and thermocouple
Air Flow
50mm / 2in
15mm / 0.6in
DUT
Total Power International, Inc
Toll Free: 877-646-0900
www.total-power.com
TOTAL-POWER [ TOTAL POWER INTERNATIONAL ]
