The NML 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.
1.0
7.0
4.5
4.5
3.7
96
67
59
53
76
63
53
45
1.2
8.5
5.2
5.5
8.5
%
200
mV p-p
ISOLATION CHARACTERISTICS
Parameter
Isolation test voltage
Resistance
Conditions
Flash tested for 1 second
Viso= 500VDC
Min.
1000
10
Typ.
Max.
Units
VDC
GΩ
ABSOLUTE MAXIMUM RATINGS
Lead temperature 1.5mm from case for 10 seconds
Input voltage V
IN
, NML05 types
Input voltage V
IN
, NML12 types
260°C
7V
15V
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
www.murata-ps.com/support
KDC_NML.F01
Page 1 of 5
NML Series
Isolated 2W Single Output DC/DC Converters
GENERAL CHARACTERISTICS
Parameter
Switching frequency
Conditions
5V input types
12V input types
Min.
Typ.
90
90
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
45
36
Units
°C
TEMPERATURE DERATING GRAPH
3
TOLERANCE ENVELOPE
+10%
+5%
V
NOM
Typical
L
oad Line
+2.5%
-2.5%
-7.5%
Output Power (W)
1
0
-40
Safe Operating Area
Output Voltage
2
85°C
10
100
50
0
Ambient Temperature (°C)
150
100
75
50
25
Output Load Current (%)
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 NML 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?”
The NML series has been recognised 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 NML 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 recognised 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 NML 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 100ºC as measured at any point on the case of the unit (hotspot).
The NML series of converters are not internally fused so to meet the requirements of UL 60950 an anti-surge input line fuse should always be used with ratings as defined below.
NML05xxSC: 0.8A
NML12xxSC: 0.315A
All fuses should be UL recognized and rated to 125V. File number E151252 applies.
www.murata-ps.com/support
KDC_NML.F01
Page 2 of 5
NML 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
790
1154
2265
2998
396
880
1156
2394
Typical Start-Up Wave Form
NML0505SC
NML0509SC
NML0512SC
NML0515SC
NML1205SC
NML1209SC
NML1212SC
NML1215SC
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
www.murata-ps.com/support
KDC_NML.F01
Page 3 of 5
NML 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
be >20MHz.
L
Power
Source
DC
C
Load
DC
NML0505SC
NML0509SC
NML0512SC
NML0515SC
NML1205SC
NML1209SC
NML1212SC
NML1215SC
L, μH
22
47
47
68
22
47
47
68
Inductor
SMD
82223
82473
82473
82683
82223
82473
82473
82683
Through Hole
11R223C
11R473C
11R473C
11R683C
11R223C
11R473C
11R473C
11R683C
Capacitor
C, μF
2.2uF
1uF
2.2uF
3.3uF
2.2uF
1uF
2.2uF
3.3uF
www.murata-ps.com/support
KDC_NML.F01
Page 4 of 5
NML Series
Isolated 2W Single Output DC/DC Converters
PACKAGE SPECIFICATIONS
MECHANICAL DIMENSIONS
SIP Package
PIN CONNECTIONS - 4 PIN SIP
Pin
1
2
3
4
Function
-V
IN
+V
IN
-V
OUT
+V
OUT
14.00±0.15 [0.551±0.006]
TUBE OUTLINE DIMENSIONS
10.00±0.25 [0.394±0.010]
NML
0505SC
XYYWW
0.40 [0.016] MIN
9.3 [0.366]
S
4.10±0.5 [0.161±0.020]
1
2
3
4
12.43 [0.489]
18.0 [0.709]
2.54 [0.100]
(3.44 [0.135])
0.50±0.05 [0.020±0.002]
0.25±0.05 [0.010±0.002]
(1.13 [0.044])
7.50±0.25 [0.295±0.010]
5.0 [0.197]
Weight: 2.0g
All dimensions in mm (inches). Controlling dimension is mm.
All pins on a 2.54 (0.100) pitch and within ±0.1 (0.004) of true position from pin 1 at seating plane ‘S’
Unless otherwise specified all dimensions in mm [inches] ±0.55mm [0.022].
Tube Length : 520mm [20.472] ±2.0 [0.079].
Tube Quantity : 35
RECOMMENDED FOOTPRINT DETAILS
RoHS COMPLIANCE INFORMATION
2.54 [0.100]
x4 HOLES
1.15 Ø 0.045
Ø 1.00
0.039
[
]
This series is compatible with RoHS soldering
systems with a peak wave solder temperature of
260°C for 10 seconds. The pin termination finish
on this product series is Tin Plate, Hot Dipped
over Matte Tin with Nickel Preplate. The series
is backward compatible with Sn/Pb soldering
systems.
2.54 [0.100]
For further information, please visit www.murata-ps.com/rohs
Unless otherwise stated all dimensions in mm (inches) ±0.5mm.
Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A.
ISO 9001 and 14001 REGISTERED
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
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
