cui.com
date 03/12/2012
page 1 of 5
SERIES: VFK400W │ DESCRIPTION: DC-DC CONVERTER
date 03/12/2012
page 1 of 5
FEATURES
• up to 400 W isolated output
• rugged metal enclosure with integrated heat sink
• 4:1 input range (10~36 V, 18~75 V)
• single output from 12~48 V
• 1,500 V isolation
• over current, over temperature, over voltage,
and short circuit protection
• remote on/off
• efficiency up to 87%
RoHS
PART NUMBER KEY
VFK400W-Q XX -S XX
Input Voltage Output Voltage
Base Number
MODEL input
voltage
output
voltage
output
current
output
power
ripple
and noise1
effi ciency
range
(Vdc) (Vdc)
max
(A)
max
(W)
max
(mVp-p)
max
(%)
VFK400W-Q24-S12 10~36 12 33.3 400 200 87
VFK400W-Q24-S24 10~36 24 16.7 400 240 86
VFK400W-Q24-S48 10~36 48 8.3 400 480 86
VFK400W-Q48-S12 20~75 12 33.6 400 200 87
VFK400W-Q48-S24 18~75 24 16.7 400 240 86
VFK400W-Q48-S48 18~75 48 8.3 400 480 86.5
Notes: 1. ripple and noise are measured at 20 MHz BW with 10μF tantalum capacitor and 1μF ceramic capacitor across output
For more information, please visit the product page.
cui.com
CUI Inc │ SERIES: VFK400W │ DESCRIPTION: DC-DC CONVERTER date 03/12/2012 │ page 2 of 5
INPUT
parameter conditions/description min typ max units
operating input voltage
24 V input
48 V input 12 V output
24, 48 V output
10
20
18
24
48
48
36
75
75
Vdc
Vdc
under voltage lockout
power up
power down
24 V input
48 V input
24 V input
48 V input
9.5
17.8
18.5
15.5
Vdc
Vdc
Vdc
Vdc
remote on/off1
Notes: 1. logic compatibility, open collector ref to -input
Module ON, 3.5~75 Vdc or open circuit
Module OFF, <1.2 Vdc
OUTPUT
parameter conditions/description min typ max units
line regulation measured from high line to low line ±1 %
load regulation measured from full load to zero load ±1 %
voltage accuracy ±1.5 %
transient response 25% step load change 500 μs
adjustability260 110 %
switching frequency 250 kHz
temperature coeffi cient ±0.03 %/°C
Notes: 2. trim-up: connect a resistor between the trim pin and +Sense
trim-down: connect a resistor between the trim pin and -Sense
PROTECTIONS
parameter conditions/description min typ max units
over voltage protection %Vo 115 140 %
over current protection % nominal output current 110 150 %
short circuit protection continuous
SAFETY AND COMPLIANCE
parameter conditions/description min typ max units
isolation voltage
input to output
input to case
output to case
1,500
1,500
1,500
Vdc
Vdc
Vdc
isolation resistance 10 MΩ
RoHS compliant yes
ENVIRONMENTAL
parameter conditions/description min typ max units
case operating temperature see derating curve -40 100 °C
maximum case temperature 110 °C
storage temperature -55 105 °C
For more information, please visit the product page.
cui.com
CUI Inc │ SERIES: VFK400W │ DESCRIPTION: DC-DC CONVERTER date 03/12/2012 │ page 3 of 5
DERATING CURVES
80%
100%
120%
f
nominal output
Natural
Convection
0.5 m/S
(100LFM)
1.0 m/S
(200LFM)
1.5 m/S
(300LFM)
0%
20%
40%
60%
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
Relative Output Power - % o
f
(300LFM)
2.0 m/S
(400LFM)
2.5 m/S
(500LFM)
3.0 m/S
(600LFM)
3.5 m/S
(700LFM)
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
Ambient Temperature - degrees C
80%
100%
120%
f
nominal output
Natural
Convection
0.5 m/S
(100LFM)
1.0 m/S
(200LFM)
1.5 m/S
(300LFM)
0%
20%
40%
60%
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
Relative Output Power - % o
f
(300LFM)
2.0 m/S
(400LFM)
2.5 m/S
(500LFM)
3.0 m/S
(600LFM)
3.5 m/S
(700LFM)
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
Ambient Temperature - degrees C
24 V input, 12 V output
48 V input, 12/24/48 V output
24 V input, 24/48 V output
For more information, please visit the product page.
cui.com
CUI Inc │ SERIES: VFK400W │ DESCRIPTION: DC-DC CONVERTER date 03/12/2012 │ page 4 of 5
MECHANICAL
parameter conditions/description min typ max units
dimensions 7.84 x 4.99 x 1.54 (199 x 126.8 x 39 mm) inch
case material steel and aluminum extrusion
weight 14.2 g
38.93 1.533
111.29 4.382
11
1
2
4
5
6
3
7
8
9
10
12
13
116.92 4.603
7.831
198.90
5.118130.00
4.50 0.177
(4 PLCS)
127.00 5.000
MECHANICAL DRAWING
units: mm[inch]
TOLERANCE:
X.X = ±0.3mm
X.XX = ±0.25mm
PIN CONNECTIONS
PIN FUNCTION
1,2 +Vin
3,4 -Vin
5 on/off
6 case
7,8 +Vo
9+S
10 Trim
11 -S
12,13 -Vo
For more information, please visit the product page.
CUI Inc │ SERIES: VFK400W │ DESCRIPTION: DC-DC CONVERTER date 03/12/2012 │ page 5 of 5
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 03/12/2012
The revision history provided is for informational purposes only and is believed to be accurate.
REVISION HISTORY
For more information, please visit the product page.
