782482 Series
ADM2482E/ADM2487E Compatible Converter Transformers
SELECTION GUIDE
Order Code
782482/33VC
782482/53VC
Nominal Input
Voltage
V
3.3
5.0
Nominal Output
Voltage
V
3.3
3.3
Isolation Voltage
V
DC
4000
4000
Turns
Ratio
1CT:1.33CT
1.14CT:1CT
Package
Style
DIL
DIL
CHARACTERISTICS
Parameter
Conditions
100kHz, 20mV
100kHz, 250mV
100kHz, 250mV
<0.1VDC
5kHz, 5V
782482/33VC
Min.
190
Max.
310
8
8
600
782482/53VC
Min.
150
Max.
260
8
8
600
Units
μH
μH
pF
mΩ
Vμs
FEATURES
RoHS compliant
Analog Devices ADM2482E/ADM2487E
compatible
4.0kV
DC
isolation
Industry-standard pinout
UL 94 V-0 package materials
Low profile
Toroidal construction
Fully encapsulated
Industrial temperature range
Surface mount versions available soon
Recommended by Analog Devices, Inc.
Backward compatible with
Sn/Pb soldering systems
Primary Inductance, L
P1
Leakage Inductance, L
L1
Interwinding Capacitance, C
WW
Primary DC Resistance, R
DC1
Volt-time Product, Et
2
13
13
ABSOLUTE MAXIMUM RATINGS
Operating free air temperature range
Storage temperature range
Isolation voltage (flash tested for 1 second)
-40°C to 85°C
-50°C to 125°C
4.0kV
DC
SOLDERING INFORMATION
3
Peak wave solder temperature
Pin finish
Specifications typical at T
A
= 25°C
1 L
P
, L
L
and R
DC
measured between pins 1-3.
2 Where pulse applied across pins 1 and 2.
3 For further information, please visit www.murata-ps.com/rohs
260˚C for 10 seconds
Matte tin
TECHNICAL NOTES
ISOLATION VOLTAGE
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 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.
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.
‘Hi Pot Test’, ‘Flash Tested’, ‘Withstand Voltage’, ‘Proof Volt-
age’, ‘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.
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.
DESCRIPTION
The 782482 series of converter transformers are
specifically designed for use with Analog Devices
chipsets to provide isolated RS-485 and RS-422
interfaces. Carefully controlled turns ratios
ensure consistent performance whilst a toroidal
construction minimises EMI.
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com
Technical enquiries
-
email:
mk@murata-ps.com,
tel:
+44 (0)1908 615232
KMP_782482C_A01
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