Rev A

DCMAW1 SERIES

1 Watt DC/DC Power Converters

12/06/2013

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

Input Reflected-Ripple Current Test Setup

Input reflected-

ripple current is measured with an 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.

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

Maximum Capacitive Load

The DCMAW1 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 8.2µF for 5VDC nominal input models, a 3.3µF for

12VDC input models, and a 1.5µF for 24VDC and 48VDC input models.