Wall Industries, Inc. 37 Industrial Drive Exeter, NH 03833

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

CMCG Series

30 Watt Single Output

2:1 Input Voltage Range

Chassis Mount DC/DC Converter

Rev. B

DESIGN & FEATURE CONSIDERATIONS

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. Negative

logic remote on/off turns the module off during a logic low and on during a logic high. 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 -0.7V to 1.0V.

A logic high is 2.5V to 100V.

The maximum sink current at the On/Off terminal (Pin 3) during a logic low is 100 mA. The maximum allowable leakage current of a switch

connected to the On/Off terminal (Pin 3) at logic high (2.5V to 100V) is 5uA.

Output Voltage Trim

Output voltage trim allows the user to increase or decrease the output voltage set point of a module.

The output voltage can be adjusted by placing an external resistor (Radj) between the Trim and +Vout or -Vout terminals. By adjusting

Radj, the output voltage can be changed by ±10% of the nominal output voltage.

A 10K, 1 or 10 Turn trimpot is usually specified for continuous trimming. Trim pin may be safely left floating if it is not used.

equation:

following equation:

Vout:

Nominal Output Voltage

Vadj:

Adjusted Output Voltage

Units:

VDC/KΩ

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.

out

adj

adj

out

)

up

(

adj

V

V

)

V

30

(

)

V

33

(

R

−

∗

−

∗

=

adj

out

out

adj

)

down

(

adj

V

V

)

V

33

(

)

V

667

.

36

(

R

−

∗

−

∗

=