Datasheet

ManualsBrandsMURATA POWER SOLUTIONS ManualsPSU ComponentsDC/DC converter (print) +15 V, -15 V 100 mA 3 W No. of outputs: 2 x

NDH Series

Isolated 3W Dual Output DC/DC Converters

KDC_NDH.C02 Page 2 of 4

www.murata-ps.com/suppor t

TEMPERATURE CHARACTERISTICS

Parameter Conditions MIN. TYP. MAX. Units

Speciﬁcation -40 85

°C

Operation -40 100

Storage -50 130

Case temperature rise above ambient 12V & 15V output types @ 100% load 36

MTTF (MEAN TIME TO FAILURE)

Part Number MTTF Units Conditions

NDH2412SC 2077

kHrs

Calculated using MIL-HDBK 217F with Nominal

input at full voltage (ground benign) at 25°C.

NDH2415SC 2080

NDH4812SC 2090

NDH4815SC 2045

GENERAL CHARACTERISTICS

Parameter Conditions MIN. TYP. MAX. Units

Control pin (CTRL) input current Please refer to control pin application note 6 15 mA

Switching frequency

Load causing lowest frequencies, 100% load VIN MIN. 100 125 150

kHz

Load causing highest frequencies, 25% load V

IN MAX. 300 400 500

ISOLATION CHARACTERISTICS

Parameter Conditions MIN. TYP. MAX. Units

Isolation test voltage Flash tested for 1 second 1000 VDC

Resistance VISO = 1000VDC 1GΩ

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.