Rev A

DCMSW1 SERIES

1 Watt DC/DC Power Converters

12/17/2013

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 SETUP

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

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. The switch can be an open coll

ector or equivalent. A logic high is 2~4mA current applied via 1KΩ resistor. A

logic low is open circuit or high impedance.

Maximum Capacitive Load

The DCMSW1 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.

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.