converters offering a single regulated output over
a 2:1 input voltage range. All parts deliver 3W
output power up to 85°C 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
recommended filter circuit for values).
Reflected ripple current
1
mA p-p
OUTPUT CHARACTERISTICS
Parameter
Voltage set point accuracy
Line regulation
Conditions
With external input/output capacitors
Low line to high line with external input/
output capacitors
0503, 0505
Min.
Typ.
±1
0.15
0.8
0.8
0.1
15
90
Max.
±3
0.5
1.0
1.2
0.5
40
150
Units
%
%
Load regulation
Minimum load to rated
load with external input/
output capacitors
2403, 2405
12V outputs
%
Ripple
Ripple & noise
BW = 20Hz to 300kHz with external input/
output capacitors
BW = DC to 20MHz with external input/output
capacitors
mV rms
mV p-p
1. Please refer to relected ripple current measurement circuit on page 2.
2. Calculated using MIL-HDBK-217F with nominal input voltage at full load (ground benign) at 25°C.
All specifications typical at T
A
=25°C, nominal input voltage and rated output current unless otherwise specified.
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com/support
KDC_NDTS.F01
Page 1 of 5
NDTS Series
Isolated 3W Single Output DC-DC Converters
ABSOLUTE MAXIMUM RATINGS
Short-circuit protection
Lead temperature 1.5mm from case for 10 seconds
Minimum output load for specification
1
Input voltage 05 types
Input voltage 12 types
Input voltage 24 types
Free air space
8 Hours
300°C
25% of rated output
10V
20V
40V
10mm Min. around component
GENERAL CHARACTERISTICS
Parameter
Switching frequency
Conditions
100% to 25% load, V
IN
Min. to Max.
Min.
70
Typ.
Max.
650
Units
kHz
ISOLATION CHARACTERISTICS
Parameter
Isolation voltage
Resistance
Conditions
Flash tested for 1 second
Resistance
Min.
1000
1
Typ.
Max.
Units
VDC
GΩ
TEMPERATURE CHARACTERISTICS
Parameter
Operation
Storage
NDTS1212C, NDTS2405C, NDTS2412C
Case temperature rise above ambient
in still air
NDTS0505C, NDTS0512C, NDTS2403C
NDTS0503C
Conditions
Min.
-40
-50
Typ.
Max.
85
125
Units
30
40
50
ºC
TECHNICAL NOTES
ISOLATION VOLTAGE
‘Hi Pot Test’, ‘Flash Tested’, ‘Withstand Voltage’, ‘Proof Voltage’, ‘Dielectric Withstand Voltage’ & ‘Isolation Test Voltage’ are all terms that relate to the same thing, a test voltage,
applied for a specified time, across a component designed to provide electrical isolation, to verify the integrity of that isolation.
Murata Power Solutions NDTS series of DC-DC converters are all 100% production tested at their stated isolation voltage. This is 1kVDC for 1 second.
A question commonly asked is, “What is the continuous voltage that can be applied across the part in normal operation?”
For a part holding no specific agency approvals, such as the NDTS series, both input and output should normally be maintained within SELV limits i.e. less than 42.4V peak, or
60VDC. The isolation test voltage represents a measure of immunity to transient voltages and the part should never be used as an element of a safety isolation system. The part
could be expected to function correctly with several hundred volts offset applied continuously across the isolation barrier; but then the circuitry on both sides of the barrier must
be regarded as operating at an unsafe voltage and further isolation/insulation systems must form a barrier between these circuits and any user-accessible circuitry according to
safety standard requirements.
REPEATED HIGH-VOLTAGE ISOLATION TESTING
It is well known that repeated high-voltage isolation testing of a barrier component can actually degrade isolation capability, to a lesser or greater degree depending on materials,
construction and environment. The NDTS series has an EI ferrite core, with no additional insulation between primary and secondary windings of enameled wire. While parts can be
expected to withstand several times the stated test voltage, the isolation capability does depend on the wire insulation. Any material, including this enamel (typically polyurethane)
is susceptible to eventual chemical degradation when subject to very high applied voltages thus implying that the number of tests should be strictly limited. We therefore strongly
advise against repeated high voltage isolation testing, but if it is absolutely required, that the voltage be reduced by 20% from specified test voltage.
This consideration equally applies to agency recognized parts rated for better than functional isolation where the wire enamel insulation is always supplemented by a further
insulation system of physical spacing or barriers.
RoHS COMPLIANCE INFORMATION
This series is compatible with RoHS soldering systems with a peak wave solder
temperature of 300ºC for 10 seconds. The pin termination finish on this product series
is Tin. The series is backward compatible with Sn/Pb soldering systems.
For further information, please visit www.murata-ps.com/rohs
1. Please refer to minimum load application note on page 4.
www.murata-ps.com/support
KDC_NDTS.F01
Page 2 of 5
NDTS Series
Isolated 3W Single Output DC-DC Converters
APPLICATION NOTES
Recommended Input & Output Capacitors
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 characterized using the following values and test circuit.
Input Voltage
5V, 12V
24V
C
IN
100μF, 25V (0.25Ω at 100kHz)
10μF, 100V (1.5Ω at 100kHz)
Output Voltage
3.3V, 5V
12V
C
OUT
220μF, 16V (0.12Ω at 100kHz)
100μF, 25V (0.25Ω at 100kHz)
Test circuit
+ V
OUT
Supply + V
IN
+ V
IN
C
IN
Supply - V
IN
- V
IN
NDTS
C
OUT
- V
OUT
Reflected Ripple Current Measurement
12
μ
H
Supply + V
IN
Current
Probe
+ V
IN
+ V
OUT
C
1
C
IN
NDTS
C
OUT
Load
Supply - V
IN
C
1
= 220μF, ESR < 0.1Ω at 100kHz
- V
IN
- V
OUT
www.murata-ps.com/support
KDC_NDTS.F01
Page 3 of 5
NDTS Series
Isolated 3W Single Output DC-DC Converters
APPLICATION NOTES (continued)
Minimum Load
The minimum load for correct operation is 25% of the full rated load across the specified input voltage range. Lower loads may cause a significant increase in output ripple and
may cause the output voltage to exceed its specification transiently during power-down when the input voltage also falls below its rated minimum.
The following graphs show the typical required minimum load required for stable operation in mA verses input voltage. Some variants are not included as they do not typically
require a minimum load for stable operation: NDTD1212C.
The NDTS series will operate from a wider input range than specified in the input characteristics datasheet table with output power derating. Please contact Murata Power
Solutions for further information.
NDTS05XXC
200
180
160
Minimum Load (mA)
140
120
100
80
60
40
20
0
4.5
5.5
6.5
7.5
8.5
Input Voltage (V)
9.5
10.5
11.5
0512
0503
0505
NDTS24XXC
200
180
160
140
Minimum Load (mA)
120
100
80
60
40
20
0
10
15
20
25
30
35
2412
40
45
2405
2403
Input Voltage (V)
www.murata-ps.com/support
KDC_NDTS.F01
Page 4 of 5
NDTS Series
Isolated 3W Single Output DC-DC Converters
PACKAGE SPECIFICATIONS
MECHANICAL DIMENSIONS
32.26 (1.270)
PIN CONNECTIONS
Pin
5.08 (0.200)
Function
-V
IN
-V
IN
NA
NC
+V
OUT
-V
OUT
+V
IN
+V
IN
NDTSXXXXC
XYYWW
14.66 (0.577)
2.54 (0.100)
2
3
9
11
14
16
22
23
7.00 (0.275)
NA - Not available for
electrical connection.
NC - No internal connection.
5.00 (0.197)
4.00 (0.157)
0.73 (0.029)
0.63 (0.025)
22.86 (0.900)
4.70 (0.185)
RECOMMENDED FOOTPRINT DETAILS
x8 HOLES
Ø
1.45 (0.057)
1.30 (0.051)
2.54 (0.1)
0.30 (0.012)
0.20 (0.008)
15.25 (0.600)
2.54(0.1)
Weight: 6.2g
All dimensions in mm(inches) ±0.25(0.010”). All pins on a 2.54(0.10”) pitch and within
±0.25(0.010”) of true position.
All dimensions in mm(inches) ±0.25(0.010”).
All pins on a 2.54(0.10”) pitch and within ±0.25(0.010”) of true position.
TUBE OUTLINE DIMENSIONS
20.70±0.55 (0.815±0.022)
16.70±0.55 (0.657±0.022)
11.70±0.80 (0.461±0.031)
6.80±0.55 (0.268±0.022)
0.60±0.15 (0.024±0.006)
All dimensions in mm (inches) ±0.5mm (0.20”).
Tube length : 520mm±2mm (20.47±0.079”).
5.50±0.25 (0.217±0.010)
16.70±0.80 (0.657±0.031)
Tube Quantity : 15
This product is subject to the following
operating requirements
and the
Life and Safety Critical Application Sales Policy:
Refer to:
http://www.murata-ps.com/requirements/
Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other
technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply
the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without
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