‘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 NTE 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?”
For a part holding no specific agency approvals, such as the NTE series, 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 NTE 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.
TEMPERATURE DERATING GRAPH
1.5
Output Power (W)
1.0
0.5
0
-40
85°C
Safe Operating Area
100
50
0
Ambient Temperature (°C)
150
1. 12V input types have typically 3% less load regulation change.
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KDC_NTE.K04
Page 2 of 6
NTE Series
Isolated 1W Single Output SM DC/DC Converters
TOLERANCE ENVELOPES
3.3V output types.
+9%
All other types.
+10%
Typical
L
V
NOM
+1%
-7%
oad Lin
e
+1%
-7%
-15%
+5%
V
NOM
Typical
L
oad Line
+2.5%
-2.5%
-7.5%
Output Voltage
Output Voltage
10
75
50
25
Output Load Current (%)
100
10
75
50
25
Output Load Current (%)
100
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.
RoHS COMPLIANCE, MSL AND PSL INFORMATION
This series is compatible with RoHS soldering systems and is also backward compatible with Sn/Pb soldering systems.
The NTE series has a process, moisture, and reflow sensitivity classification of MSL1 PSL R7F as defined in J-STD-020
and J-STD-075. This translates to: MSL1 = unlimited floor life, PSL R7F = Peak reflow temperature 245°C with a
limitation on the time above liquidus (217°C) which for this series is 60sec max. The pin termination finish on this product
series is Gold with a plating thickness of 0.05 microns minimum.
For further information please visit www.murata-ps.com/rohs
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.
NTE0303MC
NTE0305MC
NTE0309MC
NTE0312MC
NTE0315MC
NTE0503MC
NTE0505MC
NTE0505MEC
Start-up time
μs
437
1359
3435
6590
7625
533
1368
721
NTE0506MC
NTE0509MC
NTE0512MC
NTE0515MC
NTE1205MC
NTE1209MC
NTE1212MC
NTE1215MC
Start-up time
μs
7200
3146
4960
7740
895
2150
3640
7180
Typical Start-Up Wave Form
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KDC_NTE.K04
Page 3 of 6
NTE Series
Isolated 1W Single Output SM 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
NTE0303MC
NTE0305MC
NTE0309MC
NTE0312MC
NTE0315MC
NTE0503MC
NTE0505MC
NTE0505MEC
NTE0506MC
NTE0509MC
NTE0512MC
NTE0515MC
NTE1205MC
NTE1209MC
NTE1212MC
NTE1215MC
L, μH
10
47
22
10
47
10
47
47
10
22
47
47
47
22
47
47
Inductor
SMD
82103C
82473C
82223C
82103C
82473C
82103C
82473C
82473C
82103C
82223C
82473C
82473C
82473C
82223C
82473C
82473C
Through Hole
11R103C
11R103C
11R223C
11R103C
11R473C
11R103C
11R473C
11R473C
11R103C
11R223C
11R473C
11R473C
11R473C
11R223C
11R473C
11R473C
Capacitor
C, μF
4.7
4.7
2.2
1
1
4.7
4.7
4.7
4.7
2.2
1
1
4.7
2.2
1
1
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KDC_NTE.K04
Page 4 of 6
NTE Series
Isolated 1W Single Output SM DC/DC Converters
PACKAGE SPECIFICATIONS
MECHANICAL DIMENSIONS
12.70 (0.500)
7.62 (0.300)
14
12
10
8
PIN CONNECTIONS
DETAIL A
Pin
1
3
5
7
8
10
Function
-V
IN
+V
IN
NA
-V
OUT
11.20 (0.441) 7.70 (0.303)
10.40 (0.409)
NTE0505MC
XYYWW
1
3
5
7
REFERENCE
PLANE
P
0.50 (0.020)
+V
OUT
NA
NA
NA
1.50 (0.059)
1.20 (0.047)
0.65 (0.026)
0.55 (0.022)
10 PINS
0.2 (0.008)
±5.00
°
S
12
14
2.54 (0.100)
2.10 (0.083)
6.60 (0.260) 6.35 (0.250)
5.95 (0.234) 5.85 (0.230)
DETAIL A
NA - Not available for electrical connection.
SEATING
S
PLANE
2.79 (0.110) MAX
0.25 (0.010)
0.10 (0.004)
0.1(0.004) S
1.875 MAX
0.30 (0.012)
0.20 (0.008)
Weight: 1.21g
All dimensions in mm ±0.25mm (inches ±0.01). All pins on a 2.54 (0.1) pitch and within ± 0.25 (0.01) of true position.
RECOMMENDED FOOTPRINT DETAILS
TUBE OUTLINE DIMENSIONS
0.60±0.15 (0.024±0.006)
2.10 (0.083)
14.35 (0.565)
9.40 (0.370)
6.70 (0.264)
All pins on a 2.54mm pitch.
Unless otherwise stated all dimensions in mm (inches) ±0.5mm.
Unless otherwise stated all dimensions in mm±0.5mm (inches ±0.02).