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

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

Page 6 of 7

MSLU Series

1500VDC I/O Isolation

Single and Dual Outputs

1 Watt DC/DC Converters

Rev A

DESIGN & FEATURE CONSIDERATIONS

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 qualit

y 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 MSLU 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. For optimal performance we recommend a

maximum load of 33µF.

TEST CONFIGURATIONS

Input Reflected-Ripple Current Test Setup

Input reflected-ripple current is measured with an inductor Lin (4.7µH) a

nd Cin (220µF, ESR < 1.0Ω at 100KHz) 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.

+Out

-Out

+Vin

-Vin

DC / DC

Converter

Load

Battery

+

Lin

+

Cin

To Oscilloscope

Current

Probe

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