Datasheet
NDS6 Series
Isolated 6W Wide Input Single & Dual Output DC/DC Converters
KDC_NDS6.E01 Page 2 of 6
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GENERAL CHARACTERISTICS
1
Parameter Conditions Min. Typ. Max. Units
Switching frequency 130 kHz
Control pin input
Module ON (or pin unconnected)
3.0 V
0mA
Module OFF
0.8 V
1.5 mA
TEMPERATURE CHARACTERISTICS
Parameter Conditions Min. Typ. Max. Units
Operation -40 85
°C
Storage -50 130
Case temperature rise above ambient 100% Load, Nom V
IN, Still Air,
5V 29
12V & 15V 22
Thermal shutdown Case Temperature 110
APPLICATION NOTES
Control Pin NDS6D Cross Regulation
This provides an OFF function, which puts the converter into a low
power mode, when the voltage applied to the pin is less than 0.8V.
When the pin is high or un-connected, the converter is on.
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
datasheet specification, a minimum load of 10% of output load current is required on each output.
The NDS6D can be used with much lighter loading but the negative output voltage may rise above
maximum datasheet specification.
Output Capacitors
The NDS6 series does not require output capacitors to meet datasheet specification. To meet datasheet specification, output capacitance should not exceed:
Output Voltage (V) Output Capacitance (µF)
5 470
12 470
15 220
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 NDS6 series of DC/DC converters are all 100% production tested at their stated isolation voltage. This is 1.5kVDC for 1 second.
A question commonly asked is, “What is the continuous voltage that can be applied across the part in normal operation?”
The NDS6 has been recognized by Underwriters Laboratory for functional isolation. 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 NDS6 series has an ER 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.