782485 Series
www.murata-ps.com
ADM2485 Compatible Converter Transformers
SELECTION GUIDE
Nominal Input
Nominal Max. Output Isolation
Turns Package
Output Voltage Current Voltage
Voltage
Order Code
Ratio Style
V V mA VRMS
782485/35C 3.3 6.0 200 2500 1CT:2.2CT DIL
782485/55C 5.0 6.0 200 2500 1CT:1.5CT DIL
CHARACTERISTICS 782485/35C
782485/35C 782485/55C
Parameter Conditions Units
Typ. Max. Typ. Max.
FEATURES
Primary Inductance, L 100kHz, 10mV 234 513 H
P
RoHS compliant
Leakage Inductance, L 100kHz, 10mV 168 192 nH
L
Interwinding Capacitance, C 100kHz, 10mV 24 50 37 50 pF
WW
Analog Devices ADM2485 compatible
Primary DC Resistance, R <0.1VDC 273 500 383 600 m
DC
1
2.5kVrms isolation
Volt-time Product, Et 5kHz, 5V 12 19 Vs
Industry-standard pinout
ABSOLUTE MAXIMUM RATINGS
UL 94 V-0 package materials
Operating free air temperature range -40C to 85C
Low pro le Storage temperature range -50C to 125C
Isolation voltage ( ash tested for 1 second) 2.5kVrms
Toroidal construction
2
SOLDERING INFORMATION
Fully encapsulated
Peak wave solder temperature 300C for 10 seconds
Industrial temperature range
Pin nish Matte tin
Surface mount versions available soon
Speci cations typical at T = 25C
A
1 Where pulse applied across pins 1 and 2.
Recommended by Analog Devices, Inc.
2 For further information, please visit www.murata-ps.com/rohs
Backward 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
DESCRIPTION
age, Dielectric Withstand Voltage & Isolation Test Voltage testing of a barrier component can actually degrade
The 782485 series of converter transformers are
are all terms that relate to the same thing, a test voltage, isolation capability, to a lesser or greater degree
speci cally designed for use with Analog Devices
applied for a speci ed time, across a component designed depending on materials, construction and environ-
chipsets to provide isolated RS-485 and RS-422
to provide electrical isolation, to verify the integrity of that ment. This series has toroidal isolation transformers,
isolation. with no additional insulation between primary and
interfaces. Carefully controlled turns ratios
secondary windings of enameled wire. While parts
ensure consistent performance whilst a toroidal
All products in this series are 100% production tested at
can be expected to withstand several times the
their stated isolation voltage.
construction minimises EMI.
stated test voltage, the isolation capability does de-
A question commonly asked is, What is the continuous
pend on the wire insulation. Any material, including
voltage that can be applied across the part in normal opera-
this enamel (typically polyurethane) is susceptible
tion?
to eventual chemical degradation when subject to
For a part holding no speci c agency approvals both input
very high applied voltages thus implying that the
and output should normally be maintained within SELV limits
number of tests should be strictly limited. We there-
i.e. less than 42.4V peak, or 60VDC. The isolation test volt-
fore strongly advise against repeated high voltage
age represents a measure of immunity to transient voltages
isolation testing, but if it is absolutely required, that
and the part should never be used as an element of a safety
the voltage be reduced by 20% from speci ed test
isolation system. The part could be expected to function cor-
voltage.
rectly with several hundred volts offset applied continuously
This consideration equally applies to agency recog-
across the isolation barrier; but then the circuitry on both
nized parts rated for better than functional isolation
sides of the barrier must be regarded as operating at an
where the wire enamel insulation is always supple-
unsafe voltage and further isolation/insulation systems must
mented by a further insulation system of physical
form a barrier between these circuits and any user-acces-
spacing or barriers.
sible circuitry according to safety standard requirements.
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com/support
KMP_782485C_A04 Page 1 of 2782485 Series
ADM2485 Compatible Converter Transformers
PACKAGE SPECIFICATIONS
MECHANICAL DIMENSIONS RECOMMENDED FOOTPRINT DETAILS
9.77
(0.385) Max. TOP VIEW
2.54 (0.10)
Primary Secondary
1 6
2.54 (0.10)
9.14
2 5
(0.360) Max.
782485/35C
34
XYYWW
+0.15 (0.006)
1.20 (0.05)
-0.00 (0.000)
6.35
(0.25)
3.440.50
(0.1350.02)
0.30(0.012)
0.6 (0.024)
0.20(0.008)
10.160.40
2.54
(0.400.016) (0.1)
Unless otherwise stated all dimensions in mm (inches) 0.25 (0.01).
Unless otherwise stated all dimensions in mm (inches) 0.25 (0.01).
All pins on a 2.54 (0.1) pitch and within 0.25 (0.01) of true position.
Package Weight 1.0g TYP. All pins on a 2.54(0.1) pitch and within 0.25(0.01) of true position.
TUBE OUTLINE DIMENSIONS
10.65 - 11.65
(0.419 - 0.459)
Unless otherwise stated all
dimensions in mm (inches)
4.00 (0.16)
0.25 (0.01).
Tube length: 5002 (19.70.08)
0.600.15
12.95
Tube quantity: 50
(0.0240.006)
(0.51)
Tube material: Antistatic coated
clear PVC.
5.20 (0.21)
3.80
(0.15)
15.70 (0.62)
Murata Power Solutions, Inc.
Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other
11 Cabot Boulevard, Mans eld, MA 02048-1151 U.S.A. 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. Speci cations are subject to change without
ISO 9001 and 14001 REGISTERED notice. 2011 Murata Power Solutions, Inc.
www.murata-ps.com/support
KMP_782485C_A04 Page 2 of 2