Datasheet
CD5.241-S1
CD-Series 
DC/DC Converter 24V, 5A 
6.  HOLD-UP TIME 
The input side of the DC/DC converter is equipped with a bulk capacitor which keeps the output voltage alive for a 
certain period of time when the input voltage dips or is removed. The bulk capacitor can be discharged by loading the 
DC/DC converter on the output side or through a load which is parallel to the input. There is no protection in the 
DC/DC converter which prevents current from flowing back to the input terminals. If prevention is needed, an external 
diode should be used. 
Hold-up Time  typ.  11.8ms  input 24Vdc, output: 24Vdc, 2.5A, see Fig. 6-1
  typ.  6ms  input 24Vdc, output: 24Vdc, 5A, see Fig. 6-1 
  Fig. 6-1 Hold-up time vs. input voltage     
0
2
4
6
8
12ms
18 20 22 24 28Vdc
Input Voltage
Hold-up Time
(a) 24V, 2.5A, typ.
(b) 24V, 2.5A, min.
(c) 24V, 5A, typ.
(d) 24V, 5A, min.
10
26
(
a
)
(
b
)
(
c
)
(
d
)
  Fig. 6-2 Shut-down test setup    Fig. 6-3 Shut-down behavior, definitions 
Load
+
-
DC/DC
Converter
DC
Source
+
-
Input
Output
+
-
CD5
S1
- 5%
Hold-up Time
Output
Voltage
Intput
Voltage
S1 opens
Note: At no load, the hold-up time can be up to several seconds. The green DC-ok lamp is also on during this time. 
Oct 2009 / Rev. 1.3 DS-CD5.241-S1-EN 
All parameters are specified at 24V, 5A, 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 
7/22










