are ideally suited for providing dual rail supplies
on single rail boards with the added benefit of
galvanic isolation to reduce circuit noise. All of
the rated power may be drawn from a single pin
provided the total load does not exceed 2 watts.
Pin compatibility with the NMA 1 watt series
ensures minimal effort in upgrading distributed
power systems.
INPUT CHARACTERISTICS
Parameter
Voltage range
Conditions
Continuous operation, 5V input types
Continuous operation, 12V input types
Continuous operation, 24V input types
Continuous operation, 48V input types
5V input types
12V input types
24V input types
48V input types
Min.
4.5
10.8
21.6
43.2
Typ.
5
12
24
48
50
70
130
200
Max.
5.5
13.2
26.4
52.8
Package
Style
DIP
SIP
DIP
SIP
Output Output
Voltage Current
Input
Current at
Rated Load
mA
Efficiency
Isolation
MTTF
1
Capacitance
DIP
SIP
Units
V
Reflected ripple current
mA p-p
1. Calculated using MIL-HDBK-217F 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.
For full details go to
www.murata-ps.com/rohs
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KDC_NMH.F01
Page 1 of 6
NMH Series
Isolated 2W Dual Output DC/DC Converters
OUTPUT CHARACTERISTICS
Parameter
Rated Power
1
Voltage Set Point Accuracy
Line regulation
Conditions
T
A
=-40
°C
to 85
°C
NMH0505DC/SC
All other types
High V
IN
to low V
IN
10% load to rated load, 5V output types
10% load to rated load, 9V output types
10% load to rated load, 12V output types
10% load to rated load, 15V output types
BW=DC to 20MHz, 5V output types
BW=DC to 20MHz, 9V output types
BW=DC to 20MHz, 12V output types
BW=DC to 20MHz, 15V output types
Min.
-5
-5
Typ.
Max.
2
7.5
5
1.2
10
10
200
150
150
150
Units
W
%
%/%
1.0
5
3
150
100
80
70
Load Regulation
%
Ripple and Noise
mV p-p
ABSOLUTE MAXIMUM RATINGS
Lead temperature 1.5mm from case for 10 seconds
Internal power dissipation
Input voltage V
IN
, NMH05 types
Input voltage V
IN,
NMH12 types
Input voltage V
IN,
NMH24 types
Input voltage V
IN,
NMH48 types
300°C
300mW
7V
15V
28V
54V
ISOLATION CHARACTERISTICS
Parameter
Isolation test voltage
Resistance
Conditions
Flash tested for 1 second
Viso= 500V
Min.
1000
1
Typ.
10
Max.
Units
VDC
GΩ
GENERAL CHARACTERISTICS
Parameter
Switching frequency
Conditions
5V input types
12V input types
24V & 48V input types
Min.
Typ.
95
90
80
Max.
Units
kHz
TEMPERATURE CHARACTERISTICS
Parameter
Specification
Storage
Case Temperature above ambient
Cooling
Conditions
All output types
5V output types
12V output types
Free air convection
Min.
-40
-50
Typ.
Max.
85
130
Units
°C
30
25
TEMPERATURE DERATING GRAPH
3
TOLERANCE ENVELOPE
+10%
Output Voltage
Output Power (W)
2
1
0
-40
85°C
+5%
V
NOM
Typical
Load Lin
e
+2.5%
-2.5%
-7.5%
Safe Operating Area
10
100
50
0
Ambient Temperature (°C)
150
75
50
25
Output Load Current (%)
100
The voltage tolerance envelope shows typical load regulation characteristics for this
product series. The tolerance envelope is the maximum output voltage variation due
to changes in output loading.
1. See derating graph.
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KDC_NMH.F01
Page 2 of 6
NMH Series
Isolated 2W Dual Output DC/DC Converters
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 NMH 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 NMH 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 NMH 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 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
300°C for 10 seconds. The pin termination finish on the SIP package type is Tin Plate, Hot Dipped
over Matte Tin with Nickel Preplate. The DIP types are Matte Tin over Nickel Preplate. Both types in
this series are backward compatible with Sn/Pb soldering systems.
For further information, please visit www.murata-ps.com/rohs
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.
NMH0505SC
NMH0509SC
NMH0512SC
NMH0515SC
NMH1205SC
NMH1209SC
NMH1212SC
NMH1215SC
Start-up time
μs
1072
2481
3546
5380
672
1152
1580
3150
NMH2405SC
NMH2409SC
NMH2412SC
NMH2415SC
NMH4805SC
NMH4809SC
NMH4812SC
NMH4815SC
Start-up time
μs
1064
1544
4398
4230
966
1220
2822
4275
Typical Start-Up Wave Form
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KDC_NMH.F01
Page 3 of 6
NMH Series
Isolated 2W Dual Output DC/DC Converters
APPLICATION NOTES (continued)
Ripple & Noise Characterisation Method
Ripple and noise measurements are performed with the following test configuration.
1μF X7R multilayer ceramic capacitor, voltage rating to be a minimum of 3 times the output voltage of the DC/DC converter
10μF tantalum capacitor, voltage rating to be a minimum of 1.5 times the output voltage of the DC/DC converter with an ESR of less
C2
than 100mΩ at 100 kHz
C3
100nF multilayer ceramic capacitor, general purpose
R1
450Ω resistor, carbon film, ±1% tolerance
R2
50Ω BNC termination
T1
3T of the coax cable through a ferrite toroid
RLOAD
Resistive load to the maximum power rating of the DC/DC converter. Connections should be made via twisted wires
Measured values are multiplied by 10 to obtain the specified values.
C1
Differential Mode Noise Test Schematic
DC/DC Converter
OSCILLOSCOPE
C1 C2 C3
+
SUPPLY
Input
R1
T1
R2
Y INPUT
+
Output
-
-
R LOAD
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: Ceramic chip capacitors are recommended. It is required that the ESR (Equivalent Series Resistance) should be as low as possible, X7R 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 be >20MHz.
L
Power
Source
DC
C
Load
DC
C (μF)
4.7
2.2
3.3
3.3
4.7
2.2
3.3
3.3
4.7
2.2
3.3
3.3
4.7
2.2
3.3
3.3
Order Code
NMH0505XC
NMH0509XC
NMH0512XC
NMH0515XC
NMH1205XC
NMH1209XC
NMH1212XC
NMH1215XC
NMH2405XC
NMH2409XC
NMH2412XC
NMH2415XC
NMH4805XC
NMH4809XC
NMH4812XC
NMH4815XC
L (μH)
47
47
150
100
47
47
150
100
47
47
150
100
47
47
150
100
Inductor Order Codes
SMD
Through Hole
82473C
11R473C
82473C
11R473C
82154C
11R154C
82104C
11R104C
82473C
11R473C
82473C
11R473C
82154C
11R154C
82104C
11R104C
82473C
11R473C
82473C
11R473C
82154C
11R154C
82104C
11R104C
82473C
11R473C
82473C
11R473C
82154C
11R154C
82104C
11R104C
Product specification for MPS inductors can be found at:
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