CD5.121

CD-Series

DC/DC Converter 12V, 8A

Inrush current limitation

An active inrush limitation circuit (inrush limiting resistor which is bypassed by a relay contact) limits the input inrush

current after turn-on of the input voltage.

The charging current into EMI suppression capacitors is disregarded in the first microseconds after switch-on.

Inrush current

max.

-25°C to +70°C, input: 24Vdc

typ.

-25°C to +70°C, input: 24Vdc

Inrush energy

typ.

negligible

-25°C to +70°C, input: 24Vdc

Fig. 4-1 Input inrush current, typical behavior

Input Current

Input Voltage

Output Voltage

Input:

24Vdc

Output:

12V, 8A, constant current load

Ambient:

25°C

Upper curve:

Input current 2A / DIV

Middle curve:

Input voltage 20V / DIV

Lower curve:

Output voltage 10V / DIV

Time basis:

100ms / DIV

Soft-start function:

After the DC/DC converter is turned on, the internal output current rises slowly to its nominal value. This method

charges the output capacitors (internal and external capacitors) slowly and avoids high input currents during turn-on.

High input currents can produce a high voltage drop on the input wiring (especially with long and thin cables) which

reduces the terminal voltage on the DC/DC converter. If the terminal voltage is below the shut-down voltage, the

DC/DC converter will turn-off and will make a new start-up attempt. This effect is avoided with the integrated soft-

start function. Please note, that this function increases the rise time of the output voltage by a small amount.

Fig. 4-2 Soft-start behavior

Input Current

Output Voltage

Input:

24Vdc

Output:

12V, 8A, constant current load

Ambient:

25°C

No additional external output capacitors

Upper curve:

Input current 2A / DIV

Lower curve:

Output voltage 5V / DIV

Time basis:

20ms / DIV

Mar. 2016 / Rev. 1.5 DS-CD5.121-EN

All parameters are specified at 12V, 8A, 24Vdc input voltage, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

www.pulspower.com Phone +49 89 9278 0

Germany

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