SELECTION GUIDE
1
FEATURES
s
Industry Standard Footprint
s
1kVDC Isolation
s
Dual Isolated Output
s
Short Circuit Protection
s
Low Profile 24 Pin Case
s
Efficiency to 81%
s
Power Density 0.90W/cm
3
s
2:1 Wide Input Range
s
24V & 48V Input
s
12V & 15V Output
s
Footprint 4.73cm
2
s
UL 94V-0 Package Materials
s
Operating Temperature Range
40C to 85C
s
Load and Line Regulation
<1% on Both Outputs
s
No Heatsink Required
s
Internal SMD Construction
s
Fully Encapsulated
s
Custom Solutions Available
DESCRIPTION
The NDT series is a range of low profile DC-
DC converters offering dual outputs over a
2:1 input voltage range. All parts deliver 3W
output power up to 85C without heatsinking.
A flyback oscillator design with isolated
feedback is used to give regulation over the
full operating range of 25% to 100% of full
load. It is strongly recommended that external
capacitors be used on input and output to
guarantee performance over full load and
input voltage range (see application notes for
guidance). The plastic case is rated to UL
94V-0 and encapsulant to UL 94V-1and the
connection pins are formed from a tin plated
alloy 42 leadframe.
Nominal Rated
Input
Input
Output
Output Current
Current
Voltage Voltage
Min Load
3
Full Load
Full Load
MTTF
4
Order Code
(V)
(V)
(mA)
(mA)
(mA)
(%)
(pF)
kHrs
NDTD2412
24
12
31
125
156
79
30
2075
NDTD2415
24
15
25
100
155
80
30
2080
NDTD4812
48
12
31
125
77
81
30
2090
NDTD4815
48
15
25
100
77
81
30
2045
Parameter
Conditions
MIN
TYP
MAX
Units
Voltage Range
24V input types
18
24
36
VDC
48V input types
36
48
75
Reflected Ripple 24V input types with 10F at input
200
250
mA p-p
Current
48V input types with 10F at input
125
150
Short circuit protection over temperature range and input voltage range
continuous
Input Voltage, 24V types
40V
Input Voltage, 48V types
80V
Lead temperature 1.5mm from case for 10 seconds
300C
Minimum Load
25% of rated output
INPUT CHARACTERISTICS
1
OUTPUT CHARACTERISTICS
1
ABSOLUTE MAXIMUM RATINGS
1 Specifications typical at T
A
=25C, nominal input voltage and rated output current unless otherwise specified.
2 Measured at full load with external input/output capacitors, refer to test circuit.
3 A lower load is entirely safe but higher levels of output ripple will be experienced.
4 Calculated using MIL-HDBK-217F with nominal input voltage at full load.
NDT SERIES
Isolated 3W Wide Input Dual Output DC-DC Converters
www.dc-dc.com
ISOLATION CHARACTERISTICS
1
GENERAL CHARACTERISTICS
1
ENVIRONMENTAL
1
Parameter
Conditions
MIN
TYP
MAX
Units
Isolation Test Voltage
Flash tested for 1 second
1000
VDC
Resistance
Viso=1KVDC
1
G
Parameter
Conditions
MIN
TYP
MAX
Units
Switching Frequency
100% load V
IN
nominal
100
125
150
kHz
25% load V
IN
nominal
410
500
590
Parameter
Conditions
MIN
TYP
MAX
Units
Operation
40
85
C
Storage
50
130
C
Case Temperature Above Ambient 100% Load
28
C
Parameter
Conditions
MIN
TYP
MAX
Units
Rated Power
3
W
Voltage Set
With external input/output capacitors,
1
5
%
Point Accuracy
refer to recommended test circuit
Low line to high line,
Line Regulation with external input/output capacitors,
0.15
0.5
%
refer to recommended test circuit
25% load to 100% load,
Load Regulation with external input/output capacitors,
0.2
0.5
%
refer to recommended test circuit
BW = 20Hz to 300kHz
Ripple
With external input/output capacitors,
15
30
mV rms
refer to recommended test circuit
BW = DC to 20MHz
Ripple & Noise With external input/output capacitors,
90
150
mV p-p
refer to recommended test circuit
Cross
% voltage change on negative output
Regulation
when positive load varies from 12% to
2.1
3.0
%
50% with negative load fixed at 50%
NDT SERIES
Isolated 3W Wide Input Dual Output DC-DC Converters
C&D Technologies (NCL) Ltd
Tanners Drive, Blakelands North
Milton Keynes MK14 5BU, England
Tel: +44 (0)1908 615232
Fax:+44 (0)1908 617545
email: info@cdtechno-ncl.com
www: http://www.dc-dc.com
C&D Technologies Inc.
3400 E Britannia Drive, Tucson,
Arizona 85706, USA
Tel: +1 (800) 547-2537
Fax: +1 (520) 741-4598
email: sales@cdtechno.com
C&D Technologies (NCL) Limited reserve the right to alter or improve the
specification, 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 specification for your product before use.
C&D Technologies (NCL) Limited 2002
NDC NDT.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.dc-dc.com
APPLICATION NOTES
TERMINOLOGY
Weight: 6.5g
Unless otherwise stated all dimensions in inches 0.010 (mm 0.25mm).
1.270(32.26)
0.577(14.66)
0.275(7.00)
0.185(4.70)
0.145(3.70)
0.033(0.84)
0.021(0.54)
0.012(0.30)
0.008(0.20)
0.900(22.86)
0.600(15.25)Max
MECHANICAL DIMENSIONS
0.100(2.54)
LINE REGULATION
The percentage change in output voltage between low input voltage and high input voltage,
measured with fixed output load
ie. A 5V output part with an output voltage of 5.05V @ high input voltage and 5.03V @
low input voltage would have a line regulation of 0.4%.
line regulation =
V
OUT
(Low Input V) V
OUT
(High Input V)
x100%
V
OUT
(Nominal Input V)
Where V
OUT
(Nominal Input V) is 5V.
PIN CONNECTIONS
TUBE OUTLINE DIMENSIONS
EXTERNAL CAPACITANCE
Although these converters will work
without external capacitors, they ar e
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
TEST CIRCUIT
Value
C
IN
C
OUT
10F, 200V
47F, 25V
C
OUT
C
OUT
C
IN
V
IN
+V
OUT
GND
0V
V
OUT
NDT
0.185
(4.70)
0.200
(5.08)
2
23
3
22
9
16
11
14
V
IN
V
IN
Common
V
OUT
+V
IN
+V
IN
Common
+V
OUT
24 Pin DIL (top view)
PACKAGING DETAILS
Order Code
Packaging Style
QTY
NDTDXXXX
Tube
15
0.8150.022
(20.700.55)
0.2680.022
6.800.55
0.0310.006
(0.800.15)
Tube Length: 20.4720.079(520mm2mm)
Tube Material: Antistatic coated clear pvc.
0.6570.022
(16.700.55)
0.2170.001
(5.500.25)
0.6570.031
(16.700.80)
RECOMMENDED FOOTPRINT DETAILS
0.100(2.54)
0.057(1.45)
0.051(1.30)
8 Holes
0.100
(2.54)
0.1
All pins on a 0.100(2.54) pitch
and within 0.010(0.25) of true position.
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