‘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 MEJ1 series of DC/DC converters are all 100% production tested at their stated isolation voltage. This is 5.2kVDC for 1 second.
A question commonly asked is, “What is the continuous voltage that can be applied across the part in normal operation?”
The MEJ1 series has been recognized by Underwiters Laboratory for various voltages, please see safety approval section below.
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. 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.
SAFETY APPROVAL
UL 60601
The MEJ1 series has been recognized by Underwriters Laboratory (UL) to the 3rd edition of 60601 and provides the following MOOP (means of operator protection), 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): 2 MOOP based upon a working voltage of 200
Vrms max. and 280 Vpkmax., between Primary and Secondary and 1 MOOP based upon a working voltage of 200 Vrms max., between Primary and its Enclosure. File Number
E202895 applies.
UL 60950
The MEJ1 series has been recognized by Underwriters Laboratory (UL) to UL 60950 for basic/supplementary insulation to a working voltage of 200Vrms 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 E151252 applies.
FUSING
The MEJ1 Series of converters are not internally fused so to meet the requirements of UL an anti-surge input line fuse should always be used with ratings as defined below.
MEJ1x03xxSC 1A
MEJ1x05xxSC 1A
MEJ1x12xxSC 500mA
MEJ1x15xxSC 500mA
MEJ1x24xxSC 250mA
All fuses should be UL recognized and rated to at least the maximum allowable DC input voltage.
RoHS COMPLIANCE INFORMATION
This series is compatible with RoHS soldering systems with a peak wave solder temperature of 260ºC 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. For further information, please visit www.murata-ps.com/rohs
www.murata-ps.com/support
KDC_MEJ1C.A01
Page 3 of 9
MEJ1 Series
5.2kVDC Isolated 1W 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
900
2000
500
2000
3200
7500
10500
600
1200
2900
2900
3900
1100
2400
2700
3800
1700
2300
2200
3600
Start-up time
μs
700
1600
3700
4200
7000
600
1200
3600
3900
6000
1200
3200
3300
4800
1100
2000
3300
6400
Typical Start-Up Wave Form
MEJ1S0303SC
MEJ1S0305SC
MEJ1S0503SC
MEJ1S0505SC
MEJ1S0509SC
MEJ1S0512SC
MEJ1S0515SC
MEJ1S1203SC
MEJ1S1205SC
MEJ1S1209SC
MEJ1S1212SC
MEJ1S1215SC
MEJ1S1505SC
MEJ1S1509SC
MEJ1S1512SC
MEJ1S1515SC
MEJ1S2405SC
MEJ1S2409SC
MEJ1S2412SC
MEJ1S2415SC
MEJ1D0503SC
MEJ1D0505SC
MEJ1D0509SC
MEJ1D0512SC
MEJ1D0515SC
MEJ1D1203SC
MEJ1D1205SC
MEJ1D1209SC
MEJ1D1212SC
MEJ1D1215SC
MEJ1D1505SC
MEJ1D1509SC
MEJ1D1512SC
MEJ1D1515SC
MEJ1D2405SC
MEJ1D2409SC
MEJ1D2412SC
MEJ1D2415SC
Ripple & Noise Characterisation Method
Ripple and noise measurements are performed with the following test configuration.
C1
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.
Differential Mode Noise Test Schematic
DC/DC Converter
C1 C2 C3
+
SUPPLY
Input
R1
T1
R2
OSCILLOSCOPE
Y INPUT
+
Output
-
-
R LOAD
www.murata-ps.com/support
KDC_MEJ1C.A01
Page 4 of 9
MEJ1 Series
5.2kVDC Isolated 1W DC/DC Converters
TOLERANCE ENVELOPES
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.
DUAL 1203,1515, 2412, SINGLE 0303, 0305, 1203
+5%
+3%
+2%
Output Voltage
+1%
-1%
Output Voltage
DUAL 1209, 1509, 2409
0%
-7%
10
25
50
Output Load Current (%)
75
100
10
25
75
50
Output Load Current (%)
100
-3%
DUAL 0515, SINGLE 1515, 2415
DUAL 1512, SINGLE 1212, 1512, 2412
+2%
+2%
Output Voltage
Output Voltage
0%
-1%
0%
0%
-5%
-4%
10
25
50
Output Load Current (%)
75
100
10
25
50
Output Load Current (%)
75
100
DUAL 0512, SINGLE 1209, 1509,
DUAL 1212, 1215, 2415, SINGLE 0509, 0512, 1215, 2409
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