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 1 watt output at 85°C. For lower ripple,
refer to output ripple reduction section.
Ripple and Noise
1.0
14
9
7.5
7.0
5.5
85
60
50
40
140
1.2
15
10
9.5
8.5
7.5
110
75
65
55
180
%
mV p-p
ABSOLUTE MAXIMUM RATINGS
Lead temperature 1.5mm from case for 10 seconds
Internal power dissipation
Input voltage V
IN
, NME05 types
Input voltage V
IN
, NME12 types
300°C
450mW
7V
15V
1. Calculated using MIL-HDBK-217F FN2 with nominal input voltage at full load.
2. See derating curve.
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_NME.F02
Page 1 of 6
NME 5V & 12V Series
Isolated 1W Single Output DC/DC Converters
ISOLATION CHARACTERISTICS
Parameter
Isolation test voltage
Resistance
Conditions
Flash tested for 1 second
Viso= 1000VDC
Min.
1000
Typ.
10
Max.
Units
VDC
GΩ
GENERAL CHARACTERISTICS
Parameter
Switching frequency
Conditions
5V input types
12V input types
Min.
Typ.
110
145
Max.
Units
kHz
TEMPERATURE CHARACTERISTICS
Parameter
Specification
Storage
Case Temperature above ambient
Cooling
Conditions
All output types
5V output types
All other output types
Free air convection
Min.
-40
-50
Typ.
Max.
85
130
41
32
Units
°C
TEMPERATURE DERATING GRAPH
1.5
TOLERANCE ENVELOPE
+10%
+5%
V
NOM
Typical
Load Lin
e
+2.5%
-2.5%
-7.5%
Output Power (W)
0.5
0
-40
Safe Operating Area
120°C
100
50
0
Ambient Temperature (°C)
150
Output Voltage
1.0
85°C
10
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.
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 NME 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 NME 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 NME 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.
www.murata-ps.com/support
KDC_NME.F02
Page 2 of 6
NME 5V & 12V Series
Isolated 1W 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
991
3524
5630
7750
19850
682
2102
4030
6193
Typical Start-Up Wave Form
NME0505SC
NME0509SC
NME0512SC
NME0515SC
NME0524SC
NME1205SC
NME1209SC
NME1212SC
NME1215SC
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
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KDC_NME.F02
Page 3 of 6
NME 5V & 12V Series
Isolated 1W 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 be
>20MHz.
L
Power
Source
DC
C
Load
DC
NME0505SC
NME0509SC
NME0512SC
NME0515SC
NME0524xC
NME1205SC
NME1209SC
NME1212SC
NME1215SC
L, μH
47
47
68
100
100
100
47
68
100
Inductor
SMD
82473C
82473C
82683C
82104C
82104C
82104C
82473C
82683C
82104C
Through Hole
11R473C
11R473C
11R683C
11R104C
11R104C
11R104C
11R473C
11R683C
11R104C
Capacitor
C, μF
4.7uF
1uF
1uF
0.47uF
0.47
4.7uF
1uF
0.47uF
0.47uF
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KDC_NME.F02
Page 4 of 6
NME 5V & 12V Series
Isolated 1W Single Output DC/DC Converters
PACKAGE SPECIFICATIONS
MECHANICAL DIMENSIONS
DIP Package
SIP Package
11.48
(0.45)
PIN CONNECTIONS - 8 PIN DIP
Pin
1
4
5
7
Function
-V
IN
+V
IN
+V
OUT
-V
OUT
9.80 (0.386)
NME0505DC
XYYWW
11.50 (0.453)
6.00
(0.236)
PIN CONNECTIONS - 4 PIN SIP
Pin
6.80 (0.267)
10.0
(0.393)
Function
-V
IN
+V
IN
-V
OUT
+V
OUT
NME0505SC
XYYWW
1
2
3
4
0.55 (0.022)
0.45 (0.018)
4.60 (0.181)
3.60 (0.142)
1
2
3
4
0.55 (0.022)
0.45 (0.018)
4.60 (0.181)
3.60 (0.142)
1.89 (0.074)
2.77 (0.109)
7.62 (0.3)
1.25
(0.049)
5.08 (0.2)
7.62 (0.3)
7.62
(0.3)
0.55 (0.022)
0.45 (0.018)
0.30 (0.0118)
0.20 (0.0078)
1
1.09 (0.043)
4
7
0.30 (0.0118)
0.20 (0.0078)
5
1.94 (0.0763)
All dimensions in mm ±0.25mm (inches ±0.01). All pins on a 2.54 (0.1) pitch and within ±0.25 (0.01) of true position.
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