782485/55C - MURATA POWER SOLUTIONS

KMP_782485C_A04 Page 1 of 2

782485 Series

ADM2485 Compatible Converter Transformers

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www.murata-ps.com/support

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For full details go to

www.murata-ps.com/rohs

SELECTION GUIDE

Order Code

Nominal Input

Voltage

Nominal

Output Voltage

Max. Output

Current

Isolation

Voltage Turns

Ratio

Package

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

Parameter Conditions 782485/35C 782485/55C Units

Typ. Max. Typ. Max.

Primary Inductance, LP100kHz, 10mV 234 513 μH

Leakage Inductance, LL100kHz, 10mV 168 192 nH

Interwinding Capacitance, CWW 100kHz, 10mV 24 50 37 50 pF

Primary DC Resistance, RDC <0.1VDC 273 500 383 600 mΩ

Volt-time Product, Et15kHz, 5V 12 19 Vμs

ABSOLUTE MAXIMUM RATINGS

Operating free air temperature range -40°C to 85°C

Storage temperature range -50°C to 125°C

Isolation voltage (ﬂ ash tested for 1 second) 2.5kVrms

SOLDERING INFORMATION2

Peak wave solder temperature 300˚C for 10 seconds

Pin ﬁ nish Matte tin

Speciﬁ cations typical at TA = 25°C

1 Where pulse applied across pins 1 and 2.

2 For further information, please visit www.murata-ps.com/rohs

TECHNICAL NOTES

ISOLATION VOLTAGE

‘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 speciﬁ ed 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 speciﬁ c 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.

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 speciﬁ ed 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.

FEATURES

 RoHS compliant

 Analog Devices ADM2485 compatible

 2.5kVrms isolation

 Industry-standard pinout

 UL 94 V-0 package materials

 Low proﬁ le

 Toroidal construction

 Fully encapsulated

 Industrial temperature range

 Surface mount versions available soon

 Recommended by Analog Devices, Inc.

 Backward compatible with

Sn/Pb soldering systems

DESCRIPTION

The 782485 series of converter transformers are

speciﬁ cally 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.

KMP_782485C_A04 Page 2 of 2

782485 Series

ADM2485 Compatible Converter Transformers

Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other

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. Speciﬁ cations are subject to change without

Murata Power Solutions, Inc.

11 Cabot Boulevard, Mansﬁ eld, MA 02048-1151 U.S.A.

ISO 9001 and 14001 REGISTERED

www.murata-ps.com/support

PACKAGE SPECIFICATIONS

MECHANICAL DIMENSIONS RECOMMENDED FOOTPRINT DETAILS

3.44±0.50

(0.135±0.02)

6.35

(0.25)

9.14

(0.360) Max.

9.77

(0.385) Max.

Primary Secondary

0.30(0.012)

0.20(0.008) 10.16±0.40

(0.40±0.016)

0.6 (0.024)

2.54

(0.1)

782485/35C

XYYWW

2.54 (0.10)

Ø1.20 (0.05)+0.15 (0.006)

-0.00 (0.000)

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.

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.

TUBE OUTLINE DIMENSIONS

0.60±0.15

(0.024±0.006)

4.00 (0.16)

5.20 (0.21)

10.65 - 11.65

(0.419 - 0.459)

12.95

(0.51)

3.80

(0.15)

15.70 (0.62)

Unless otherwise stated all

dimensions in mm (inches)

±0.25 (0.01).

Tube length: 500±2 (19.7±0.08)

Tube quantity: 50

Tube material: Antistatic coated

clear PVC.

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