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NDH Series
www.murata-ps.com
Isolated 3W Dual Output DC/DC Converters
Isolation
Capacitance
Min Load3 Full Load
Efficiency
(MIN.)
Order Code
Output Current
Input
Current2
Input
Voltage
Rated Output
Voltage
SELECTION GUIDE
V (NOM.)
V
mA
mA
mA
%
pF
NDH2412SC
24
±12
±32
125
157
81
36
NDH2415SC
24
±15
±25
100
155
82
36
FEATURES
Recommended
Alternative
Obsolete
„
RoHS compliant
„ Compact SIP form factor
NDH4812SC
48
±12
±32
125
78
78
40
Contact Murata
„ 2:1 Wide range voltage input
NDH4815SC
48
±15
±25
100
78
78
40
Contact Murata
„ Continuous short circuit protection with
current foldback
INPUT CHARACTERISTICS
„ Operating temperature range
–40°C to +85°C
„ 0.5% Load Regulation
„ 1kVDC Isolation
Parameter
Voltage range
Reflected ripple current
Shutdown Power
„ 24V & 48V nominal input
Conditions
All NDH24 types
All NDH48 types
All NDH24 types when 10μF at input
All NDH48 types when 10μF at input
VIN Nominal 24XX
VIN Nominal 48XX
„ 12V & 15V Output
OUTPUT CHARACTERISTICS
„ Power density 1.00W/cm3
Parameter
Conditions
Voltage set point accuracy With external input/output capacitors
Low line to high line with external input/
Line regulation
output capacitors
Minimum load to rated load with external
Load regulation
input/output capacitors
BW = 20Hz to 300kHz with external input/
Ripple
output capacitors
Ripple & noise
BW = DC to 20MHz with external input/
output capacitors
„ Remote on/off
„ No electrolytic capacitors
„ Low noise
PRODUCT OVERVIEW
The NDH series is a range of high performance miniature DC/DC converters having
regulated outputs over the wide temperature
range of –40°C to +85°C. The input voltage
range is 2:1 and the input to output isolation
is 1kVDC. Continuous short circuit protection, external control and extremely small SIP
packaging provide state of the art functionality. The use of ceramic capacitors and a
ceramic substrate, and SMD construction,
provide genuine high reliability. Nominal input
voltages of 24 and 48V with output voltages
of 12 and 15V are available as standard with
custom parts on request. The plastic case
is rated to UL 94V-0 with encapsulant to UL
94V-1.
Cross regulation
% voltage change on negative output when
positive load varies from 12% to 50% with
negative load fixed at 50%
MIN.
18
36
MIN.
TYP.
24
48
200
105
8
16
MAX.
36
72
250
150
Units
TYP.
±1
MAX.
±5
Units
%
0.05
0.2
%
0.2
0.5
%
15
30
mV rms
90
150
mV p-p
2.1
5.0
%
V
mA p-p
mW
ABSOLUTE MAXIMUM RATINGS
Short-circuit protection
Lead temperature 1.5mm from case for 10 seconds
Minimum output load for specification3
Control pin input current
Input voltage 24 types1
Input voltage 48 types1
Free air space
Continuous
300°C
25% of rated output
15mA
40V
80V
10mm MIN. around component
1. Absolute maximum value for 30 seconds. Prolonged operation may damage the product.
2. Measured at full load with external input/output capacitors. Refer to application note.
3. A lower load condition can be used but higher levels of output ripple may be experienced, this condition may also cause the output
voltage to exceed its specification transiently during power down when the input voltage also falls below its rated minimum.
All specifications typical at TA=25°C, Nominal input voltage and rated output current unless otherwise specified.
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com/support
KDC_NDH.C02 Page 1 of 4
NDH Series
Isolated 3W Dual Output DC/DC Converters
TEMPERATURE CHARACTERISTICS
Parameter
Specification
Operation
Storage
Case temperature rise above ambient
Conditions
MIN.
-40
-40
-50
TYP.
12V & 15V output types @ 100% load
MAX.
85
100
130
36
Units
°C
MTTF (MEAN TIME TO FAILURE)
Part Number
NDH2412SC
NDH2415SC
NDH4812SC
NDH4815SC
MTTF
2077
2080
2090
2045
GENERAL CHARACTERISTICS
Parameter
Conditions
Control pin (CTRL) input current
Please refer to control pin application note
Units
Conditions
Calculated using MIL-HDBK 217F with Nominal
input at full voltage (ground benign) at 25°C.
kHrs
MIN.
TYP.
6
MAX.
Units
15
mA
Load causing lowest frequencies, 100% load VIN MIN.
100
125
150
Load causing highest frequencies, 25% load VIN MAX.
300
400
500
TYP.
MAX.
kHz
Switching frequency
ISOLATION CHARACTERISTICS
Parameter
Conditions
MIN.
Isolation test voltage
Resistance
Flash tested for 1 second
VISO = 1000VDC
1000
1
Units
VDC
GΩ
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 NDH 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 NDH 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 NDH series has an EI ferrite core, 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.
www.murata-ps.com/support
KDC_NDH.C02 Page 2 of 4
NDH Series
Isolated 3W Dual Output DC/DC Converters
APPLICATION NOTES
External capacitance
Although these converters will work without external capacitors, they are necessary in order to guarantee the full parametric performance over the full line and load
range. All parts have been tested and characterized using the following values and
test circuit.
Value
CIN
10μF, 200V
COUT
47μF, 25V
Test circuit
+VOUT
COUT
+VIN
NDH
CIN
OV
-VIN
COUT
-VOUT
Control Pin
The NDH converters have a shutdown feature which enables the user to put the converter into a low power state. The control pin connects directly to the base of an
internal transistor, and the switch off mechanism for the NDH works by forward biasing this NPN transistor. If the pin is left open (high impedance), the converter will be
ON (there is no allowed low state for this pin), but once a control voltage is applied with sufficient drive current, the converter will be switched OFF. A suitable application
circuit is shown below.
NDH
VIN
R2
VC
OV
-VIN
R1
D1
CTRL
Q1
D1 (eg 1N4001) is required to provide high impedence when the signal
is low. From the NDH specification, the drive current to operate this
function is recommended to be 6mA, and hence the value of R1 can be
derived as follows:
R1 =
VC - VD - VQ
IC
Assuming VC=5V, VD=0.7V and VQ=1V:
R1= 5 - 0.7 - -31.0 = 550Ω
6 x 10
Cross Regulation
Load regulation is at its best when the positive and negative loads are balanced. When the loads are asymmetric, the negative output is not as tightly regulated as the
positive output. To meet ripple specification a total minimum load of 25% full load is required, however, the NDH can be used with much lighter loading at the expense
of increased ripple. A small load is required on the negative output of 150mW to ensure the maximum negative output voltage is not exceeded.
Cross regulation is defined as change in the negative output voltage as a percentage of nominal as the positive output load is changed from 12.5% to 50% with the
negative load is fixed at 50% of full load.
RoHS COMPLIANCE INFORMATION
This series is compatible with RoHS soldering systems with a peak wave solder temperature of 300ºC
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_NDH.C02 Page 3 of 4
NDH Series
Isolated 3W Dual Output DC/DC Converters
PACKAGE SPECIFICATIONS
MECHANICAL DIMENSIONS
PIN CONNECTIONS
1.02 (25.95)
0.36 (9.25)
0.49 (12.45)
NDH2412SC
XYYWW
1 2 3
0.181(4.60)
0.142(3.60)
6 7 8 9
0.3 (7.62)
Pin
1
2
3
6
7
8
9
Function
-VIN
+VIN
CTRL
+VOUT
0V
N/A
-VOUT
Package weight: 6.5g
0.1 (2.54)
N/A - Not available for electrical
connection
0.16
(4.05)
0.107±0.02 (2.73±0.5)
0.022 (0.55)
0.018 (0.45)
Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A.
ISO 9001 and 14001 REGISTERED
0.012 (0.30)
0.008 (0.20)
All pins on a 0.1(2.54) pitch and
within ±0.01(0.25) of true position.
Unless otherwise stated all
dimensions in inches(mm)
±0.01(0.25).
This product is subject to the following operating requirements
and the Life and Safety Critical Application Sales Policy:
Refer to: http://www.murata-ps.com/requirements/
Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other
technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply
the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without
notice.
© 2013 Murata Power Solutions, Inc.
www.murata-ps.com/support
KDC_NDH.C02 Page 4 of 4
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