additional external load capacitance the rise time of the input voltage will determine the maximum external
capacitance value for guaranteed start up. The slower the rise time of the input voltage the greater the maximum value of the
additional external capacitance for reliable start up.
INPUT CHARACTERISTICS
Parameter
Voltage range
Conditions
Continuous operation, 5V input types
Continuous operation, 12V input types
Continuous operation, 15V input types
Continuous operation, 24V input types
Min.
4.5
10.8
13.5
21.6
Typ.
5
12
15
24
7.5
Max.
5.5
13.2
16.5
26.4
15
Units
V
PRODUCT OVERVIEW
The NMG series of DC/DC Converters is
particularly suited to isolating and/or converting
DC power rails. The galvanic isolation allows the
device to be configured to provide an isolated
negative rail in systems where only positive rails
exist. The wide temperature range guarantees
startup from –40°C and full 2 watt output at
85°C.
Reflected ripple current
mA p-p
ABSOLUTE MAXIMUM RATINGS
Lead temperature 1.5mm from case for 10 seconds
Input voltage V
IN
, NMG05 types
Input voltage V
IN,
NMG12 types
Input voltage V
IN,
NMG15 types
Input voltage V
IN,
NMG24 types
260°C
7V
15V
18V
28V
OUTPUT CHARACTERISTICS
Parameter
Rated Power
Voltage Set Point Accuracy
Line regulation
Conditions
T
A
=-40
°C
to 85
°C
See tolerance envelope
High V
IN
to low V
IN
Min.
Typ.
Max.
2
Units
W
%/%
1.05
1.2
For full details go to
www.murata-ps.com/rohs
1. See Ripple & Noise characterisation method.
2. Calculated using MIL-HDBK-217F FN2 with nominal input voltage at full load.
All specifications typical at T
A
=25°C, nominal input voltage and rated output current unless otherwise specified.
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KDC_NMG.E03
Page 1 of 7
MTTF
2
NMG Series
Isolated 2W Single Output DC/DC Converters
ISOLATION CHARACTERISTICS
Parameter
Isolation test voltage
Resistance
Conditions
Flash tested for 1 second
Viso= 1000VDC
Min.
1000
10
Typ.
Max.
Units
VDC
GΩ
GENERAL CHARACTERISTICS
Parameter
Switching frequency
Conditions
24V output types
All other types
Min.
Typ.
70
60
Max.
Units
kHz
TEMPERATURE CHARACTERISTICS
Parameter
Specification
Storage
Case Temperature above
ambient
Cooling
Conditions
All output types
5V input types and 5V output types
All other types
Free air convection
Min.
-40
-50
Typ.
Max.
85
125
30
25
Units
°C
EFFICIENCY VS LOAD
5V Input
90
80
70
60
NMG0512SC
NMG0505SC
NMG0509SC
NMG0515SC
NMG0524SC
12V Input
90
80
70
60
Efficiency (%)
50
40
30
20
10
0
NMG1205SC
NMG1209SC
NMG1212SC
NMG1215SC
NMG1224SC
Efficiency (%)
50
40
30
20
10
0
0
10
20
30
40
50
Load (%)
60
70
80
90
100
0
10
20
30
40
50
Load (%)
60
70
80
90
100
15V Input
90
80
70
60
NMG1505SC
24V Input
90
80
70
60
NMG2405SC
NMG2409SC
NMG2412SC
Efficiency (%)
Efficiency (%)
NMG1509SC
50
40
30
20
10
0
0
10
20
30
40
50
Load (%)
60
70
NMG1512SC
NMG1515SC
50
40
30
20
10
0
NMG2415SC
80
90
100
0
10
20
30
40
50
Load (%)
60
70
80
90
100
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KDC_NMG.E03
Page 2 of 7
NMG Series
Isolated 2W Single Output DC/DC Converters
TEMPERATURE DERATING GRAPH
3
Output Power (W)
2
1
0
-40
85°C
Safe Operating Area
100
50
0
Ambient Temperature (°C)
150
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 NMG series of DC/DC converters are all 100% production tested at their stated isolation voltage. This is 1kVDC for 1 minute.
A question commonly asked is, “What is the continuous voltage that can be applied across the part in normal operation?”
The NMG series has been recognized by Underwriters Laboratory for functional insulation. 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 materi-
als, construction and environment. The NMG series has toroidal isolation transformers, 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 lim-
ited. 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.
SAFETY APPROVAL
The NMG series has been recognised by Underwriters Laboratory (UL) to UL 60950 for functional insulation in a maximum ambient temperature of 85ºC and/or case temperature
limit of 130ºC. Case temperature measured on the face opposite the pins. File number E151252 applies.
The NMG Series of converters are not internally fused so to meet the requirements of UL 60950 an input line fuse should always be used. An anti-surge 2A should be used for
NMG05xxSC models, and an anti-surge 0.75A should be used for NMG12xxSC models. All fuses should be UL approved and rated to at least the maximum allowable DC input
voltage.
RoHS COMPLIANCE INFORMATION
This series is compatible with RoHS soldering systems with a peak wave solder temperature
of 260°C for 10 seconds. The pin termination finish is Tin Plate, Hot Dipped over Matte Tin with
Nickel Preplate. This series are backward compatible with Sn/Pb soldering systems. For further
information, please visit www.murata-ps.com/rohs
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KDC_NMG.E03
Page 3 of 7
NMG Series
Isolated 2W Single Output DC/DC Converters
APPLICATION NOTES
Minimum load
The minimum load to meet datasheet specification is 10% of the full rated load across the specified input voltage range. Lower than 10% minimum loading will result
in an increase in output voltage, which may rise to typically double the specified output voltage if the output load falls to less than 5%.
Capacitive loading and start up
Typical start up times for this series, with a typical input voltage rise time of 2.2μs and output capacitance of 10μF, are shown in the table below. The product
series will start into a capacitance of 47μF with an increased start time, however, the maximum recommended output capacitance is 10μF.
Start-up time
μs
444
1120
1930
3470
409
1320
1320
2270
2200
1400
Start-up time
μs
100
170
300
450
80
130
220
330
Typical Start-Up Wave Form
NMG0505SC
NMG0509SC
NMG0512SC
NMG0515SC
NMG1205SC
NMG1209SC
NMG1212SC
NMG1215SC
NMG0524SC
NMG1224SC
NMG1505SC
NMG1509SC
NMG1512SC
NMG1515SC
NMG2405SC
NMG2409SC
NMG2412SC
NMG2415SC
Ripple & Noise Characterisation Method
All measurement to be taken with the following components connected to the UUT as detailed below. 50 Ohm coax cable, solder connections one end, BNC plug
at the other end.
C1
C2
C3
R1
R2
T1
RLOAD
Measured values are multiplied by 10 to obtain the specified values.
1μF X7R multilayer ceramic capacitor rated at minimum 3 x the output voltage of the UUT
10μF tantalum capacitor rated at minimum 1.5 x the output voltage of the UUT with ESR of less than 100 milliohms at 100 kHz e.g. AVX TPS
series.
100nF multilayer ceramic capacitor, general purpose
450 Ohm resistor, carbon film, ±1%
50 Ohm BNC termination
3T of the coax cable through a ferrite toroid eg Ferroxcube TN32/19/13-3E25
Resistive load at the UUT maximum rating. Connections via twisted wires.
Differential Mode Noise Test Schematic
DC/DC Converter
OSCILLOSCOPE
C1 C2 C3
+
SUPPLY
Input
R1
T1
R2
Y INPUT
+
Output
-
-
R LOAD
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KDC_NMG.E03
Page 4 of 7
NMG Series
Isolated 2W Single Output DC/DC Converters
APPLICATION NOTES (continued)
Output Ripple Reduction
By using the values of inductance and capacitance stated, the output ripple at the rated load is lowered to 5mV p-p max.
Component selection
Capacitor: It is required that the ESR (Equivalent Series Resistance) should be as low as possible, ceramic types are recommended.
The voltage rating should be at least twice (except for 15V output), the rated output voltage of the DC/DC converter.
Inductor: The rated current of the inductor should not be less than that of the output of the DC/DC converter. At the rated current, the DC resistance of the
inductor should be such that the voltage drop across the inductor is <2% of the rated voltage of the DC/DC converter. The SRF (Self Resonant Frequency) should
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