Rev A

DCMCU2 SERIES

2 Watt DC/DC Power Converters

12/30/2013

Wall Industries, Inc. • 37 Industrial Drive, Exeter, NH 03833 • Tel: 603-778-2300 • Toll Free: 888-597-9255 •

Fax 603-778-9797

website: www.wallindustries.com • e-mail: sales@wallindustries.com

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TEST CONFIGURATIONS

Peak-to-Peak Output Noise Measurement Test

Use a 0.47µF 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.

DESIGN & FEATURE CONSIDERATIONS

Remote On/Off

Negative logic remote on/off turns the module OFF during a logic high voltage on the remote on/off pin and ON during a logic low. To turn

the module ON and OFF, the user must supply a switch to control the voltage between the on/off terminal and the -Vin terminal. A logic high

is 2~4mA current applied via 1K

Ω resistor. A logic low is open circuit or high impedance.

Maximum Capacitive Load

The DCMCU2 series has a limitation of maximum connected capacitance on the output. The power module may be operated in current

limiting mode during start-up, affecting the ramp-up and the start-up time. The maximum capacitance can be found in the model selection

table.

Over Current Protection

To provide protection in a fault (output overload) condition, the unit is equipped with internal current limiting circuitry and can endure

overload 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.

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 4.7µF for 12VDC nominal input models and 2.2µF for 24VDC and 48VDC nominal

input models.

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 3.3µF capacitors at the output.