MEV1 Series
3kVDC Isolated 1W Single & Dual Output DC/DC Converters
TEMPERATURE DERATING GRAPH
TOLERANCE ENVELOPE
5%
1.5
2%
0%
85°C
1.0
VNOM
0.5 Safe Operating Area
-4%
100
75
Output Load Current (%)
10 25
50
0
-40
100
Ambient Temperature (°C)
150
0
50
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 MEV1 series of DC/DC converters are all 100% production tested at their stated isolation voltage. This is 3kVDC for 1 minute.
A question commonly asked is, “What is the continuous voltage that can be applied across the part in normal operation?”
The MEV1 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 materials,
construction and environment. The MEV1 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.
SAFETY APPROVAL
The MEV1 series has been recognized by Underwriters Laboratory (UL) to UL 60950 for functional insulation in a maximum ambient temperature of 85°C and/or case temperature
limit of 130°C (case temperature measured on the face opposite the pins). File number E179522 applies.
The MEV1 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.
MEV1x05xxxC: 1A
MEV1x12xxxC: 0.375A
MEV1x15xxxC: 0.375A
MEV1x24xxxC: 0.2A
MEV1x48xxxC: 0.1A
All fuses should be UL recognized and rated to at least the maximum allowable DC input voltage.
RoHS COMPLIANT 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
www.murata-ps.com
Technical enquiries email: mk@murata-ps.com, tel: +44 (0)1908 615232
2011-05-09 KDC_MEV1.F01 Page 4 of 10
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