Rev B

DHW40 SERIES

40 Watts

DC/DC Power Converter

Single & Dual Outputs

1/9/2018

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 < 1.0

Ω 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-

500KHz.

Peak-to-Peak Output Noise Measurement Test

Use a 1µF ceramic capacitor and a 10µF tantalum 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.

TECHNICAL NOTES

Remote On/Off

Positive logic remote on/off turns the module on during a logic high voltage on the remote on/off pin, and off during a logic low. To turn the power 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 collector or

equivalent. A logic low is 0V to 1.2V. A logic high is 4.7V to 12V. The maximum sink current at the on/off terminal (Pin 3) during a logic low is -100µA.

The maximum allowable leakage current of a switch connected to the on/off terminal (Pin 3) at logic high (2.5V to 100V) is 5µA.

Over Load Protection

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

overload for an unlimited duration.

Over Voltage Protection

The output over voltage clamp consists of control circuitry, which is independent of the primary regulation loop that monitors the voltage on the output

terminals. The control loop of the clamp has a higher voltage set point than the primary loop. This provides a redundant voltage control that reduces the

risk of output overvoltage. The OVP level can be found in data sheet.

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. 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<1.0

Ω at 100KHz) capacitor of a 10µF for the 24V and 48V devices.