ideally suited for providing dual rail supplies on
primarily digital boards with the added benefit of
galvanic isolation to reduce switching noise. All of
the rated power may be drawn from a single pin
provided the total load does not exceed 1 watt.
ABSOLUTE MAXIMUM RATINGS
Lead temperature 1.5mm from case for 10 seconds
Input voltage V
IN
, NMA05 types
Input voltage V
IN,
NMA12 types
Input voltage V
IN,
NMA15 types
260°C
7V
15V
18V
For full details go to
www.murata-ps.com/rohs
1. Calculated using MIL-HDBK-217FN2 calculation model 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.
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KDC_NMA.G03
Page 1 of 6
NMA 5V, 12V & 15V Series
Isolated 1W Dual Output DC/DC Converters
OUTPUT CHARACTERISTICS
Parameter
Rated Power
Voltage Set Point Accuracy
Line regulation
Conditions
T
A
=-40
°C
to 120
°C, see derating graph
See tolerance envelope
High V
IN
to low V
IN
5V & 12V input
5V output types
9V output types
12V output types
15V output types
5V output types
12V output types
15V output types
Min.
Typ.
Max.
1
Units
W
%/%
Load Regulation
10% load to rated load
15V input
BW=DC to 20MHz, 5V output types
BW=DC to 20MHz, 9V output types
BW=DC to 20MHz, 12V output types
BW=DC to 20MHz, 15V output types
Ripple and Noise
1
1.0
10
9
6.5
6
5.5
2.6
2.3
10
7
7.5
8
1.2
12.5
10
7.5
7.0
10
3.0
3.0
20
15
15
15
%
mV p-p
ISOLATION CHARACTERISTICS
Parameter
Isolation test voltage
Resistance
Conditions
Flash tested for 1 second
Viso= 1000VDC
Min.
1000
Typ.
10
Max.
Units
VDC
GΩ
GENERAL CHARACTERISTICS
Parameter
Switching frequency
Conditions
5V input types
12V input types
15V input types
Min.
Typ.
110
140
90
Max.
Units
kHz
TEMPERATURE CHARACTERISTICS
Parameter
Specification
Storage
Conditions
All output types
0505, 1205
0509, 0512, 0515, 1209, 1212, 1215
1505
1512, 1515
Free air convection
Min.
-40
-50
Typ.
Max.
85
130
Units
Case Temperature above ambient
33
28
26
17
°C
Cooling
TEMPERATURE DERATING GRAPH
1.5
TOLERANCE ENVELOPE
+10%
85°C
+5%
V
NOM
Output Power (W)
1.0
0.5
0
-40
Typical
Load Lin
e
+2.5%
-2.5%
-7.5%
Safe Operating Area
120°C
100
50
0
Ambient Temperature (°C)
150
Output Voltage
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.
1. See Ripple & Noise characterisation method.
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KDC_NMA.G03
Page 2 of 6
NMA 5V, 12V & 15V Series
Isolated 1W Dual 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 NMA 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 NMA 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 NMA 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 COMPLIANT 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 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
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.
Typical Start-Up Wave Form
Start-up time
μs
2018
6610
14520
20200
1061
3935
Start-up time
μs
9765
15980
1060
1627
6275
NMA0505xC
NMA0509xC
NMA0512xC
NMA0515xC
NMA1205xC
NMA1209xC
NMA1212xC
NMA1215xC
NMA1505xC
NMA1512xC
NMA1515xC
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KDC_NMA.G03
Page 3 of 6
NMA 5V, 12V & 15V Series
Isolated 1W Dual Output DC/DC Converters
APPLICATION NOTES (continued)
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
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
NMA0505xC
NMA0509xC
NMA0512xC
NMA0515xC
NMA1205xC
NMA1209xC
NMA1212xC
NMA1215xC
NMA1505xC
NMA1512xC
NMA1515xC
L, μH
22
100
150
220
22
47
150
220
22
150
220
Inductor
SMD
82223C
82104C
82154C
82224C
82223C
82473C
82154C
82224C
82223C
82154C
82224C
Through Hole
11R223C
11R104C
11R154C
11R224C
11R223C
11R473C
11R154C
11R224C
11R223C
11R154C
11R224C
Capacitor
C, μF
2.2uF
0.47uF
0.33uF
1uF
2.2uF
1uF
0.33uF
1uF
2.2uF
0.33uF
2.2uF
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KDC_NMA.G03
Page 4 of 6
NMA 5V, 12V & 15V Series
Isolated 1W Dual Output DC/DC Converters
PACKAGE SPECIFICATIONS
MECHANICAL DIMENSIONS
PIN CONNECTIONS - 14 PIN DIP
DIP package
19.50 [0.768]
SIP package
19.50 [0.77]
Pin
1
7
Function
-V
IN
NC
OV
+V
OUT
-V
OUT
+V
IN
9.80 [0.386]
6.00 [0.236]
NMA0515DC
XYYWW
8
9
11
0.40 [0.016] MIN
14
6.8 [0.268]
10.00 [0.394]
PIN CONNECTIONS - 7 PIN SIP
Pin
Function
+V
IN
-V
IN
-V
OUT
OV
+V
OUT
NMA0515SC
XYYWW
1
2
4
5
6
4.10±0.50 [0.161±0.020]
7.62 [0.300]
0.50±0.05 [0.020±0.002]
4.10±0.50 [0.161±0.020]
1
2
4
5
6
2.37 0.093
2.08 0.082
1.40 0.055
1.04 0.041
[ ]
7
0.50±0.05 [0.020±0.002]
2.54 [0.100]
[ ]
1
14
0.25±0.05 [0.010±0.002]
11
9
8
1.45
1.00
[
0.057
]
0.039
[ ]
12.70 [0.500]
0.25±0.05 [0.010±0.002]
7.62 [0.300]
15.24 [0.600]
2.52 0.099
1.54 0.061
Controlling dimension is mm.
Unless otherwise stated all dimensions in mm (inches) ±0.25mm (0.010”).
All pins on a 2.54mm (0.100”) pitch and within 0.25mm (0.010”) of true position.
C++ 属于面向对象的编程语言，OOP的思想不必多说，特别对于复杂的软件工程来说，利用OOP绝对是事半功倍，相对于传统的C来说； 当然用C来写单片机程序无可厚非，已经延续了一个传统，从大学时学的开始到工作岗位，好多人都是一直用C来做，但是既然Keil支持C++编译， 可以用C++来编写你的代码，可以利用高级语言来结构化，清晰化你的程序，为嘛不用呢！哈哈，个人看法！下面进入正题： C+...[详细]
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