are ideally suited for providing local supplies on
control system boards with the added benefit of
3kVDC galvanic isolation.
ISOLATION CHARACTERISTICS
Parameter
Isolation test voltage
Resistance
Conditions
Flash tested for 1 minute
Viso= 1000VDC
Min.
3000
10
Typ.
Max.
Units
VDC
GΩ
GENERAL CHARACTERISTICS
Parameter
Switching frequency
Conditions
Min.
Typ.
60
Max.
Units
kHz
TEMPERATURE CHARACTERISTICS
Parameter
Specification
Storage
Case Temperature rise
above ambient
Cooling
MEV3S0505SC
All other types
Free air convection
Conditions
All output types, see safety approval section
for UL temperature specification
Min.
-40
-50
Typ.
Max.
85
125
37
35
Units
°C
ABSOLUTE MAXIMUM RATINGS
Lead temperature 1mm from case for 10 seconds
Wave Solder
Input voltage V
IN
, MEV05 types
Input voltage V
IN,
MEV12 types
260°C
Wave Solder profile not to exceed the profile recom-
mended in IEC 61760-1 Section 6.1.3. Please refer to
application notes
for further information.
7V
15V
For full details go to
www.murata-ps.com/rohs
1. See Ripple & Noise characterisation method.
2. Calculated using MIL-HDBK-217F FN2 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.
www.murata.com
KDC_MEV3.D01
Page 1 of 10
MTTF
2
MEV3 Series
3kVDC Isolated 3W Single 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 MEV3 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 MEV3 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 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 materi-
als, construction and environment. The MEV3 series has toroidal isolation transformers, with no additional insulation between primary and secondary windings of enamelled 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 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 MEV3 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 MEV3 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 2.5A should be used for
MEV3S05xxSC models, and an anti-surge 1A should be used for MEV3S12xxSC models. All fuses should be UL approved 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
260°C for 10 seconds. Please refer to
application notes
for further information. The pin termination
finish on the SIP package type is Tin Plate, Hot Dipped over Matte Tin with Nickel Preplate. They are
backward compatible with Sn/Pb soldering systems.
For further information, please visit www.murata-ps.com/rohs
PART NUMBER STRUCTURE
MEV 3 S XX XX S C
Series name
Power rating
Output type
S - Single
D - Dual
RoHS compliant
Package type
S - SIP
D - DIP
M - Surface mount
Z - ZIP
Input voltage
Output voltage
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KDC_MEV3.D01
Page 2 of 10
MEV3 Series
3kVDC Isolated 3W Single Output DC-DC Converters
CHARACTERISATION TEST METHODS
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
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
165
300
650
1200
75
200
350
410
Typical Start-Up Wave Form
MEV3S0505SC
MEV3S0509SC
MEV3S0512SC
MEV3S0515SC
MEV3S1205SC
MEV3S1209SC
MEV3S1212SC
MEV3S1215SC
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KDC_MEV3.D01
Page 3 of 10
MEV3 Series
3kVDC Isolated 3W 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.
L
Power
Source
DC
C
Load
DC
MEV3S0505SC
MEV3S0509SC
MEV3S0512SC
MEV3S0515SC
MEV3S1205SC
MEV3S1209SC
MEV3S1212SC
MEV3S1215SC
L, μH
10
22
47
47
10
22
47
47
Inductor
SMD
Through Hole
84103C
11R103C
84223C
11R223C
84473C
11R473C
84473C
11R473C
84103C
11R103C
84223C
11R223C
84473C
11R473C
84473C
11R473C
Capacitor
C, μF
4.7
2.2
1
1
4.7
2.2
1
1
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KDC_MEV3.D01
Page 4 of 10
MEV3 Series
3kVDC Isolated 3W Single Output DC-DC Converters
OUTPUT VOLTAGE TOLERANCE ENVELOPE
The voltage tolerance envelope shows typical load regulation characteristics for this product series. The tolerance envelope is the maximum output voltage variation due to
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