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NDX SERIES
Isolated 7.5W Wide Input Dual Output DC/DC Converters
NDC NDX1.0
Page 1 of 3
FEATURES
2:1 Wide Range Voltage Input
Continuous Short Circuit Protection
with Current Foldback
Operating Temperature Range
40C to 85C
0.2% Typical Load Regulation
1kVDC Isolation
Effi ciency from 81%
24V & 48V Nominal Input
12V & 15V Dual Outputs
Power Density 0.94W/cm
3
Remote On/Off
UL 94V-0 Package Materials
No Electrolytic Capacitors
Low Noise
Custom Solutions Available
DESCRIPTION
The NDX series of DC/DC converters
provide up to 7.5W of output power with
dual outputs. Unbalanced loading capability
with an optional input control pin which will
shutdown the NDX from TTL levels. Input
voltages of 24V (18V to 36V) and 48V (36V
to 75V) with outputs of 12V or 15V are
provided. The device is housed in a 5 sided
metal case potted with UL 94V-0 rated
material. The pinout is an industry standard
5 pin arrangement with an additional
optional control pin.
SELECTION GUIDE
1
Order Code
2
Input
Voltage
Output
Voltage
Output Current
Input Current
Effi ciency
(min)
Isolation
Capacitance
12.5%
Load
50%
Load
0%
Load
100%
Load
Shut
Down
V (nom.)
V
mA
mA
mA
mA
mA
%
pF
NDXD2412
24
12
78.1 312
6.3
380
0.4
81
56
NDXD2415
24
15
62.5 250
7.0
380
0.4
82
56
NDXD4812
48
12
78.1 312
5.9
190
0.5
82
57
NDXD4815
48
15
62.5 250
5.9
190
0.5
82
58
INPUT CHARACTERISTICS
1
Parameter
Conditions
Min.
Nom.
Max.
Units
Voltage range
24V input types
18
24
36
VDC
48V input types
36
48
75
Refl ected ripple current
24V input types with 10F at input
260
mA p-p
48V input types with 10F at input
130
OUTPUT CHARACTERISTICS
1
Parameter
Conditions
Min.
Nom.
Max.
Units
Rated Power
7.5
W
Voltage Set Point Accuracy With external input/output capacitors
2
5
%
Line regulation
Low line to high line.
With external input/output capacitors
0.04
0.4
%
Load regulation
25% total load to 100% total load
With external input/output capacitors
0.2
0.75
%
Ripple
BW=20Hz to 300kHz
With external input/output capacitors
5.0
10
mV
rms
Noise
BW=DC to 60MHz
With external input/output capacitors
50
150
mVp-p
Cross Regulation
% voltage change on negative output
when positive load varies from 12.5% to
50% with negative load fi xed at 50%
2.5
5
%
ABSOLUTE MAXIMUM RATINGS
Short-circuit protection (MAX case temperature rise 90C above
ambient)
Continuous
Internal power dissipation
2.3W
Lead temperature 1.0mm from case for 10 seconds (to JEDEC
JESD22-B106 ISS C)
260C
Minimum output load for specifi cation
12.5% of rated load on each output
Control pin input voltage
7V
Input voltage, NDXD24 types
40V
Input voltage, NDXD48 types
80V
1. Specifi cations typical at T
A
Specifi cations typical at T
Specifi cations typical at T =25C, with recommended input/output capacitors (refer to application note), nominal input voltage and
rated output current unless otherwise specifi ed.
2. If optional CTRL pin is required (as indicated in the mechanical dimensions section) suffi x the part number with an `E' when ordering
e.g. NDXD2412E.
ISOLATION CHARACTERISTICS
2
Parameter
Conditions
Min.
Nom.
Max.
Units
Isolation test voltage
Flash tested for 1 second
1000
VDC
Resistance
Viso = 1kVDC
1
G
www.cd4power.com
NDX SERIES
Isolated 7.5W Wide Input Dual Output DC/DC Converters
NDC NDX1.0
Page 2 of 3
GENERAL CHARACTERISTICS
1
Parameter
Conditions
Min.
Nom.
Max.
Units
Switching Frequency
100% total load to 25% total load
100
620
kHz
Package Weight
20
g
Control Pin Input Voltage
Module ON (or pin unconnected)
-0.6
0.8
V
-0.1
0.2
mA
Module OFF
3.0
7.0
V
0.3
3.0
mA
TEMPERATURE CHARACTERISTICS
Parameter
Conditions
Min.
Nom.
Max.
Units
Operation
-40
85
C
Storage
-50
130
Case Temperature Rise
100% Load, Nom V
IN
IN
IN
, Still Air
35
MEAN TIME TO FAILURE (MTTF)
3
Part Number
0C
25C
Units
NDXD2412
2590
1528
kHrs
NDXD2415
2492
1462
NDXD4812
2587
1558
NDXD4815
2351
1379
1. Specifi cations typical at T
A
T
T =25
C, nominal input voltage and rated output current unless otherwise specifi ed.
2. All data taken at T
A
All data taken at T
All data taken at T =25
C
3. Calculated using MIL-HDBK-217F with nominal input voltage at full load.
APPLICATION NOTES
External Capacitance
Although these converters will work without external capacitors,
they are necessary in order to guarantee the full parametric
performance over the full line and load range. All parts have
been tested and characterised using the following values and test
circuit.
Value
C
IN
C
OUT
10F, 200V
100F, 25V
Recommended Input & Output Capacitors
Control Pin
Cross Regulation
This provides an OFF function, which puts the converter into a low
power mode. When the pin is high the converter is OFF. Standard
TTL levels can be used but the maximum high level must not
exceed 7.0V. The pin can be left open for normal operation or a
voltage below 0.8V with respect to the -V
IN
pin.
Load regulation is at its best when the positive and negative loads are balanced. When
the loads are asymmetric, the negative output is not as tightly regulated as the positive
output. To meet ripple specifi cation a total minimum load of 25% full load is required,
however, the NDX can be used with much lighter loading at the expense of increased
ripple. A small load is required on the negative output of 150mW to ensure the maxi-
mum negative output voltage is not exceeded.
Cross regulation is defi ned as change in the negative output voltage as a percentage of
nominal as the positive output load is changed from 12.5% to 50%. The negative load is
fi xed at 50% of full load.
NDXD
C
IN
+V
OUT
- V
IN
+
+V
IN
-V
OUT
OV
C
OUT
C
OUT
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NDX SERIES
Isolated 7.5W Wide Input Dual Output DC/DC Converters
NDC NDX1.0
Page 3 of 3
C&D Technologies (NCL) Limited reserve the right to alter or improve the specifi cation, internal design or manufacturing process at any
time, without notice. Please check with your supplier or visit our web site to ensure that you have the current and complete specifi cation for
your product before use.
C&D Technologies (NCL) Limited 2005
NDC NDX.1
No part of this publication may be copied, transmitted or stored in a retrieval system or reproduced in any way including, but not limited
to, photography, photocopy, magnetic or other recording means, without prior written permission from C&D Technologies (NCL) Limited.
Instructions for use are available from www.cd4power.com
C&D Technologies (NCL) Ltd
Tanners Drive, Blakelands North
Milton Keynes MK14 5BU, UK
Tel: +44 (0)1908 615232
Fax: +44 (0)1908 617545
email: info@cdtechno-ncl.com
C&D Technologies, Inc.
3400 E Britannia Drive, Tucson,
Arizona 85706, USA
Tel: +1 (800) 547-2537
Fax: +1 (520) 741-4598
email: pedmktg@cdtechno.com
PACKAGE SPECIFICATIONS
MECHANICAL DIMENSIONS
PIN CONNECTIONS
Pin
Function
1
-V
IN
IN
2
+V
IN
IN
3*
CTRL
4
+V
OUT
OUT
5
OV
6
-V
OUT
OUT
Package weight: 20g
RECOMMENDED FOOTPRINT DETAILS
TUBE OUTLINE DIMENSIONS
PACKAGING DETAILS
Order Code
Packaging
Qty
NDXXXXX
Tube
15
NDXD2412
XYYWW
0.984
(25.00)
1.260
(32.00)
0.394 (10.00)
0.189
0.157
4.80
4.00
0.041
0
0.35
35
1.04
0.90
0.90
(
( ))
*
0.200
(5.08)
0.200
(5.08)
0.392
(9.96)
0.230
(5.84)
0.800 (20.32)
0.800
(20.32)
0.400
(10.16)
0.092 (2.34)
1
2
3
4
5
6
*
*
*
*
0.100 (2.54)
0.100 (2.54)
0.069
0.063
1.75
1.60
18.60)
0.0310.006
(0.800.15)
0.2360.020
(6.000.50)
* Optional pin
Unless otherwise stated all dimensions
in inches (mm)
0.010" (0.25mm).
All pins on a 0.100 (2.54) pitch and
within 0.010 (0.25) of true position.
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