Wall Industries, Inc. 5 Watson Brook Road Exeter, NH 03833

603-778-2300 www.wallindustries.com Fax 603-778-9797

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MSLUH Series

3000VDC I/O Isolation

Single and Dual Outputs

1 Watt DC/DC Converters

Rev B

DESIGN & FEATURE CONSIDERATONS

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. A 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 100KHz)

capacitor of 2.2μF for the 5V input models, a 1.0μF for the 12V input models, and a 0.47μF for the 24V input models.

+

+Out

-Out

+Vin

-Vin

DC / DC

Converter

Load

DC Power

Source

+

-

Cin

Maximum Capacitive Load

The MSLUH series has a limit 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 Model Selection Table.

TEST CONFIGURATIONS

Peak-to-Peak Output Noise Measurement Test

Use a Cout 0.33μF ceramic capacitor.

Scope measurement should be made by using a BNC socket; measurement bandwidth is 0 ~ 20MHz. Position the load

between 50mm and 75mm from the DC/DC Converter.

+Out

-Out

+Vin

-Vin

Single Output

DC / DC

Converter

Resistive

Load

Scope

Copper Strip

Cout

+Out

-Out

+Vin

-Vin

Dual Output

DC / DC

Converter

Resistive

Load

Scope

Copper Strip

Cout

Com.

Scope

Cout

Output Ripple Reduction

A good quality low ESR capacitor placed as close as possible across the load will give the best ripple and noise performance.

To reduce output ripple, it is recommended to use 1.0μF capacitors at the output.

+Out

-Out

+Vin

-Vin

Load

DC Power

Source

+

-

Cout

Single Output

DC / DC

Converter

+Out

-Out

+Vin

-Vin

Load

DC Power

Source

+

-

Cout

Com.

Dual Output

DC / DC

Converter

Copper Strip

Copper Strip

Copper Strip