Puls CD Series - Input Inrush Current; Soft-Start Feature

CD10.241
CD-Series
DC/DC Converter 24V/24V, 10A, 240W
Sep. 2019 / Rev. 1.4 DS-CD10.241-EN All values are typical figures specified at 24Vdc input voltage 24V, 10A output load,
25°C ambient and after a 5 minutes run-in time unless otherwise noted.
www.pulspower.com Phone +49 89 9278 0 Germany
7/27
4. I
NPUT
I
NRUSH
C
URRENT
An active inrush limitation circuit (inrush limiting NTC resistor which is bypassed by a MOSFET) 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. 8A At +25°C ambient, cold start
Max. 25A At +60°C ambient, cold start
Typ. 6A
peak
At +25°C ambient, cold start
Typ. 22A
peak
At +60°C ambient, cold start
Inrush energy
Max. 1A
2
s Between -25°C to +70°C, cold start
Fig. 4-1 Typical input inrush current behavior at
nominal load and 25°C ambient
Input: 24Vdc
Output: 24V, 10A, constant current load
Ambient: 25°C
Input current 2A / DIV
Input voltage 5V / DIV
Output voltage 5V / DIV
Time basis: 100ms / DIV
5. S
OFT
-
START
F
EATURE
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.