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date 12/17/2013
page 1 of 8
SERIES: VFK600 │ DESCRIPTION: DC-DC CONVERTER
FEATURES
• up to 700 W isolated output
• rugged metal enclosure with integrated heat sink
• 2:1 input range (18~36 Vdc, 36~75 Vdc)
• single output from 12~48 Vdc
• 1,500 Vdc isolation
• over current, over temperature, over voltage,
and short circuit protections
• remote on/off
• N+1 current sharing
• efficiency up to 92%
PART NUMBER KEY
VFK600 - DXX - SXX
Input Voltage
Output VoltageBase Number
MODEL input
voltage
output
voltage
output
current
output
power
ripple
and noise1
efciency
range
(Vdc) (Vdc)
max
(A)
max
(W)
max
(mVp-p)
typ
(%)
VFK600-D24-S12 18 ~ 36 12 50 600 120 89
VFK600-D24-S24 18 ~ 36 24 25 600 240 91
VFK600-D24-S28 18 ~ 36 28 21.5 600 280 90
VFK600-D24-S32 18 ~ 36 32 19 608 320 91
VFK600-D24-S48 18 ~ 36 48 12.5 600 480 92
VFK600-D48-S12 36 ~ 75 12 50 600 120 90
VFK600-D48-S24 36 ~ 75 24 25 600 240 91
VFK600-D48-S28 36 ~ 75 28 25 700 280 91
VFK600-D48-S32 36 ~ 75 32 19 608 320 92
VFK600-D48-S48 36 ~ 75 48 12.5 600 480 92
Notes: 1. Ripple and noise are measured at full load, 20 MHz BW with 10µF tantalum capacitor and 1µF ceramic capacitor across output
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CUI Inc │ SERIES: VFK600 │ DESCRIPTION: DC-DC CONVERTER date 12/17/2013 │ page 2 of 8
INPUT
parameter conditions/description min typ max units
operating input voltage 24 Vdc input models
48 Vdc input models
18
36
24
48
36
75
Vdc
Vdc
input current 24 Vdc input models, Vin = 18 Vdc, full load
48 Vdc input models, Vin = 36 Vdc, full load
37.7
21.7
A
A
under voltage shutdown
24 Vdc input power up
power down
16
15
17
16
18
17
Vdc
Vdc
48 Vdc input power up
power down
34
32
35
33
36
34
Vdc
Vdc
over voltage shutdown
24 Vdc input power up
power down
38
40
Vdc
Vdc
48 Vdc input power up
power down
77
80
Vdc
Vdc
CTRL1positive logic models ON (3.5~7.5 Vdc or open circuit)
models OFF (0~0.7 Vdc)
input fuse 60 A time delay fuse for 24 Vin models,
30 A time delay fuse for 48 Vin models
lter pi lter
Note: 1. Open collector refer to -Vin.
OUTPUT
parameter conditions/description min typ max units
maximum capacitive load 12 V output models
24~48 V output models
470
470
10,000
5,000
μF
μF
line regulation measured from low line to high line ±0.2 %
load regulation measured from zero load to full load ±0.5 %
voltage accuracy ±1.5 %
load share accuracy 50~100% load ±10 %
adjustability 60 110 %
switching frequency 48 V input, 12/28/32 V output models
all other models
300
250
kHz
kHz
transient response 25% step load change 500 µs
temperature coefcient ±0.03 %/°C
PROTECTIONS
parameter conditions/description min typ max units
short circuit protection continuous
over current protection % nominal output current 110 150 %
over voltage protection %Vo 115 140 %
over temperature protection shutdown 110 °C
SAFETY AND COMPLIANCE
parameter conditions/description min typ max units
isolation voltage for 1 minute: input to output; input to case;
output to case 1,500 Vdc
isolation resistance 10 MΩ
RoHS 2011/65/EU (CE)
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CUI Inc │ SERIES: VFK600 │ DESCRIPTION: DC-DC CONVERTER date 12/17/2013 │ page 3 of 8
199.14 7.840
4.50 0.177
( 4 PLCS)
116.68 4.594
130.00 5.118
1
2
3
4
5
6
39.12 1.540
111.29 4.381
126.75 4.990
7
8
9
10
11
12
13
14
ENVIRONMENTAL
parameter conditions/description min typ max units
operating temperature see derating curves -40 85 °C
storage temperature -55 105 °C
MECHANICAL
parameter conditions/description min typ max units
dimensions 199.14 x 126.75 x 39.12 (7.84 x 4.99 x 1.54 inch) mm
case material steel and aluminum extrusion
weight 1.2 kg
MECHANICAL DRAWING
PIN CONNECTIONS
PIN FUNCTION
1, 2 +Vin
3 REM
4 case
5, 6 -Vin
7, 8 +Vo
9 +S
10 PC
11 Trim
12 -S
13, 14 -Vo
units: mm[inch]
tolerance: X.XX = ±0.5[±0.02]
X.XXX = ±0.25[±0.010]
wire range: 22~12 AWG
screw size: #6-32
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CUI Inc │ SERIES: VFK600 │ DESCRIPTION: DC-DC CONVERTER date 12/17/2013 │ page 4 of 8
DERATING CURVES
0%
20%
40%
60%
80%
100%
120%
0510 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85
Ambient Temperature - degrees C
Relative Output Power - % of nominal output
Natural
Convection
0.5 m/S
(100LFM)
1.0 m/S
(200LFM)
1.5 m/S
(300LFM)
2.0 m/S
(400LFM)
2.5 m/S
(500LFM)
3.0 m/S
(600LFM)
3.5 m/S
(700LFM)
0%
20%
40%
60%
80%
100%
120%
0510 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85
Ambient Temperature - degrees C
Relative Output Power - % of nominal output
Natural
Convection
0.5 m/S
(100LFM)
1.0 m/S
(200LFM)
1.5 m/S
(300LFM)
2.0 m/S
(400LFM)
2.5 m/S
(500LFM)
3.0 m/S
(600LFM)
3.5 m/S
(700LFM)
VFK600 Power Derating Curves At Nominal Input
(Includes 24 V input, 12/24/28 V output models and VFK600-D48-S12)
VFK600 Power Derating Curves At Nominal Input
(Includes 24 V input, 32/48 V output models and 48 V input, 24/28/32/48 V output models)
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CUI Inc │ SERIES: VFK600 │ DESCRIPTION: DC-DC CONVERTER date 12/17/2013 │ page 6 of 8
APPLICATION NOTES
STANDARD PARALLEL CONNECTION PARALLEL CONNECTION WITH PROGRAMMED AND
ADJUSTABLE OUTPUT
N+1 REDUNDANT CONNECTION WITH PROGRAMMED
OUTPUT AND ADJUSTABLE OUTPUT VOLTAGE
N+1 REDUNDANT CONNECTION
+S
+V
-V
-S
PC
+S
+V
-V
-S
PC
L
O
A
D
+S
+V
-V
-S
PC
TRIM
TRIM
+S
+V
-V
-S
PC
L
O
A
D
+S
+V
-V
-S
PC
+S
+V
-V
-S
PC
L
O
A
D
TRIM
TR
IM
+S
+V
-V
-S
PC
+S
+V
-V
-S
PC
L
O
A
D
1. Parallel Operation
The VFK600 series are designed for parallel operation. When in parallel the load current can be shared equally between the two
modules by connecting their PC pins. The VFK600 can be setup in two different modes to achieve parallel operation. The stan
dard parallel operation is suitable when load cannot be handled by a single unit, whereas the N+1 redundant operation is suitable
for loads when backup power is required.
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CUI Inc │ SERIES: VFK600 │ DESCRIPTION: DC-DC CONVERTER date 12/17/2013 │ page 7 of 8
Figure 3
External DC Voltage
APPLICATION NOTES (CONTINUED)
+S
+V
-V
-S
TRIM
Rt
Load
VR
Rt
Rt
Rt
Rt
Vf
+
×
+
+
×
×
=
33
33
7. 86
)
33
33
(
)
(
1. 42
VfVRVoVout ×+=)(
V
T
V
O
Vout ×=
Note: 1. All specications measured at nominal line, full load, and 25°C unless otherwise specied.
2. Output Voltage Trimming
Leave open if not used.
Figure 2
Trim-Up/Trim-Down Formulas
Trim-Up/Trim-Down Formulas
External Resistors
Note: Rt = 6.8 KΩ
VO is the nominal output voltage
VOUT is the desired output voltage (up or down)
VR is the trim resistor in KΩ
Note: VT is the trim terminal voltage
VO is the nominal output voltage
VOUT is the desired output voltage (up or down)
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CUI Inc │ SERIES: VFK600 │ DESCRIPTION: DC-DC CONVERTER date 12/17/2013 │ page 8 of 8
CUI offers a two (2) year limited warranty. Complete warranty information is listed on our website.
CUI reserves the right to make changes to the product at any time without notice. Information provided by CUI is believed to be accurate and reliable. However, no responsibility is
assumed by CUI for its use, nor for any infringements of patents or other rights of third parties which may result from its use.
CUI products are not authorized or warranted for use as critical components in equipment that requires an extremely high level of reliability. A critical component is any component of a
life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness.
Headquarters
20050 SW 112th Ave.
Tualatin, OR 97062
800.275.4899
Fax 503.612.2383
cui.com
techsupport@cui.com
rev. description date
1.0 initial release 11/04/2011
1.01 derating curves added 03/12/2012
1.02 V-Innity branding removed 08/07/2012
1.03 updated spec 03/13/2013
1.04 added parallel operation and trimming information 12/17/2013
The revision history provided is for informational purposes only and is believed to be accurate.
REVISION HISTORY
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