Datasheet

NMG Series
Isolated 2W Single Output DC/DC Converters
KDC_NMG.E02 Page 3 of 7
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TEMPERATURE DERATING GRAPH
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 sys-
tem. 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 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 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
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
150100
50
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-40
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2
3
Safe Operating Area
85°C
Ambient Temperature (°C)
Output Power (W)
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.