1605C
www.murata-ps.com
Lan-Pak for CSMA/CD Systems
SELECTION GUIDE
Min.
Max.
Leakage
Inductance
Max.
Inerwinding
Capacitance
Max.
Min.
Primary
DC Resistance ET Constant
Order Code
Turns Ratio
Inductance
μH
26.0
Ω
0.2
Vμs
1.8
μH
0.2
pF
8
1605C
1:1
ABSOLUTE MAXIMUM RATINGS
Operating free air temperature range
Storage temperature range
0°C to 70°C
-60°C to 125°C
500Vrms
FEATURES
Isolation voltage (flash tested for 1 second)
SOLDERING INFORMATION1
Peak wave solder temperature, 1.5mm from case
Pin finish
nRoHS compliant
300˚C for 10 seconds
Matte Tin
n500Vrms isolation
nIndustry-standard footprint
nCompatible with standard networks
All specifications typical at TA=25°C.
1 For further information, please visit www.murata-ps.com/rohs
nBackward compatible with
Sn/Pb soldering systems
TECHNICAL NOTES
ISOLATION VOLTAGE
REPEATED HIGH-VOLTAGE ISOLATION TESTING
‘Hi Pot Test’, ‘Flash Tested’, ‘Withstand Voltage’, ‘Proof Volt-
It is well known that repeated high-voltage isolation
age’, ‘Dielectric Withstand Voltage’ & ‘Isolation Test Voltage’ testing of a barrier component can actually degrade
DESCRIPTION
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.
isolation capability, to a lesser or greater degree
depending on materials, construction and environ-
ment. This 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 de-
pend 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 there-
fore 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.
The 1605C is a package of unity-turns-ratio
isolation transformers. The transformers are
designed to have fast rise times with low phase
shift and insertion loss to reduce signal distortion.
The high shunt impedance of these devices
minimises system loading and enables the correct
termination conditions to be accurately defined by
means of resistors. The devices can be used as
network-node isolators in CSMA/CD systems.
All products in this series are 100% production tested at
their stated isolation voltage.
A question commonly asked is, “What is the continuous
voltage that can be applied across the part in normal opera-
tion?”
For a part holding no specific agency approvals both input
and output should normally be maintained within SELV limits
i.e. less than 42.4V peak, or 60VDC. The isolation test volt-
age 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 cor-
rectly 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-acces-
sible circuitry according to safety standard requirements.
This consideration equally applies to agency recog-
nized parts rated for better than functional isolation
where the wire enamel insulation is always supple-
mented by a further insulation system of physical
spacing or barriers.
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com/support
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