78253/35JC - MURATA MANUFACTURING

78253J Series

MAX253 Compatible Converter SM Transformers

Technical enquiries email: mk@murata-ps.com, tel: +44 (0)1908 615232

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

For full details go to

www.murata-ps.com/rohs

FEATURES

 J-STD-020D reﬂow

 RoHS compliant

Maxim MAX253 compatible

3.3V and 5V versions

Isolation to 4kVDC

Frequency range to 500kHz

Toroidal construction

Industry-standard pinout

UL 94 V-0 package materials

Low proﬁle

Industrial temperature range

DESCRIPTION

The 78253 series of converter transformers are

speciﬁcally designed for use with the MAX253

chip set to provide isolated power supplies. The

5V input version can supply 1W and the 3.3V

input version can supply 500mW. A centre tapped

secondary winding allows for full bridge, half

bridge or voltage doubling.

For through hole versions see 78253 series

datasheet.

SELECTION GUIDE

Order Code Input Voltage Output

Voltage

Max. Output

Current

Isolation

Voltage Turns

Ratio

V V mA VDC

78253/35JC 3.3 5.0 100 1500 1:2.27

78253/55JC 5.0 5.0 200 1500 1:1.31

78253/35JVC 3.3 5.0 100 4000 1:2.14

78253/55JVC 5.0 5.0 200 4000 1:1.33

ORDER CODE DETAILS

Order Code Package Type Packaging Type Quantity

78253/XXJ(V)C 6 Pin SM Tube 50

78253/XXJ(V)C-R 6 Pin SM Tape & Reel 500

78253/35JC CHARACTERISTICS

Parameter Conditions Min. Typ. Max. Units

Primary Inductance, LP100kHz, 250mV 0.27 0.36 0.50 mH

Secondary Inductance, LS100kHz, 250mV 1.60 2.00 2.40 mH

Leakage Inductance, LL100kHz, 250mV 0.32 1.00 μH

Interwinding Capacitance, CWW 100kHz, 250mV 24 50 pF

Primary D.C. Resistance, RDC >0.1VDC 0.5 1.00 Ω

Volt-time Product, Et Pins 1/2 or 2/3 30 49 Vμs

78253/55JC CHARACTERISTICS

Parameter Conditions Min. Typ. Max. Units

Primary Inductance, LP100kHz, 250mV 0.57 0.83 1.10 mH

Secondary Inductance, LS100kHz, 250mV 1.10 1.40 1.70 mH

Leakage Inductance, LL100kHz, 250mV 0.51 1.00 μH

Interwinding Capacitance, CWW 100kHz, 250mV 30 50 pF

Primary D.C. Resistance, RDC >0.1VDC 0.70 1.50 Ω

Volt-time Product, Et Pins 1/2 or 2/3 40 70 Vμs

78253/35JVC CHARACTERISTICS

Parameter Conditions Min. Typ. Max. Units

Primary Inductance, LP100kHz, 20mV 110 142 203 μH

Secondary Inductance, LS100kHz, 20mV 550 710 850 μH

Leakage Inductance, LL100kHz, 250mV 3.46 5.00 μH

Interwinding Capacitance, CWW 100kHz, 250mV 2 8.00 pF

Primary D.C. Resistance, RDC >0.1VDC 0.30 0.50 Ω

Volt-time Product, Et Pins 1/2 or 2/3 18 30 Vμs

78253/55JVC CHARACTERISTICS

Parameter Conditions Min. Typ. Max. Units

Primary Inductance, LP100kHz, 20mV 170 240 335 μH

Secondary Inductance, LS100kHz, 20mV 350 444 540 μH

Leakage Inductance, LL100kHz, 250mV 6.28 8.00 μH

Interwinding Capacitance, CWW 100kHz, 250mV 3.4 8.00 pF

Primary D.C. Resistance, RDC >0.1VDC 0.40 0.60 Ω

Volt-time Product, Et Pins 1/2 or 2/3 25 37 Vμs

All speciﬁcations typical at TA=25°C

78253J Series

MAX253 Compatible Converter SM Transformers

Technical enquiries email: mk@murata-ps.com, tel: +44 (0)1908 615232

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PACKAGE SPECIFICATIONS

MECHANICAL DIMENSIONS

RECOMMENDED FOOTPRINT DETAILS

ABSOLUTE MAXIMUM RATINGS

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

Storage temperature range -50°C to 125°C

Peak current IPK 400mA

Isolation voltage 78253/XXJC (ﬂash tested for 1 second) 1500VDC

Isolation voltage 78253/XXJVC (ﬂash tested for 1 second) 4000VDC

Unless otherwise stated all dimensions in inches (mm) ±0.01 (0.25).

All pins on a 0.1 (2.54) pitch and within ±0.01 (0.25) of true position.

Package weight 1.0g Typ.

0.45

(11.50)

0.10 (2.54)

0.04

(1.00)

0.06 (1.60)

Unless otherwise stated all dimensions in inches (mm) ±0.01 (0.25).

All pins on a 0.1 (2.54) pitch and within ±0.01 (0.25) of true position.

0.354

(9.0) MAX

0.375

(9.52) MAX

0.5

(12.70)

0.025 (0.63)

0.021 (0.53)

0.1

(2.54)

0.035

(0.90)

0.012 (0.30)

0.008 (0.20)

0.25

(6.35)

78253/55JC

XYYWW

Primary Secondary

Top View

78253J Series

MAX253 Compatible Converter SM Transformers

Technical enquiries email: mk@murata-ps.com, tel: +44 (0)1908 615232

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TYPICAL CHARACTERISTICS (VOLTAGE CURVES)

VOLTAGE CURVES

Output Voltage (V)

Output Current (mA) Output Current (mA)

Output Voltage (V)

Output Current (mA) Output Current (mA)

EFFICIENCY CURVES

Efﬁciency (%)

Output Current (mA) Output Current (mA)

Efﬁciency (%)

Output Current (mA) Output Current (mA)

All curves are derived from testing with the Maxim MAX235 IC using the circuit shown in application note MPAN-03 ( download at http://www.murata-ps.com/data/apnotes/mpan-03.pdf).

020 40 60 80 100 120

78253/35JC

400

78253/55JC

0100 200 300

78253/35JVC

020 40 60 100

78253/55JVC

0100 200 300 400

78253/35JC

100

020 40 60 120

80 100

78253/55JC

100

00200 400

300

100

78253/35JVC

020 40 60 100

100

78253/55JVC

100

00200 400

300

100

78253J Series

MAX253 Compatible Converter SM Transformers

Technical enquiries email: mk@murata-ps.com, tel: +44 (0)1908 615232

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TYPICAL CHARACTERISTICS (VOLTAGE CURVES) continued

VOLTAGE DEVIATION

Voltage Deviation from Nominal

25°C Output (%)

Voltage Deviation from Nominal

25°C Output (%)

Temperature (°C) Temperature (°C)

Voltage Deviation from Nominal

25°C Output (%)

Voltage Deviation from Nominal

25°C Output (%)

Temperature (°C) Temperature (°C)

78253/35JC

110

105

100

-50 050

-25 75 100

78253/55JC

110

105

100

-50 050

-25 75 100

78253/35JVC

110

105

100

-50 050

-25 75 100

78253/55JVC

110

105

100

-50 050

-25 75 100

SOLDERING INFORMATION1

Pin ﬁnish Matte tin

Max. peak reﬂow temperature 245°C

Moisture sensitivity level21

Max. time above liquidous (217°C) 100s

TUBE OUTLINE DIMENSIONS

All speciﬁcations typical at TA=25°C

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

2 Representative samples of the product were subjected to the conditioning described in

IPC/JEDEC J-STD-020D and passed electrical testing, package coplanarity and visual

inspection which revealed no external cracks or changes in package body ﬂatness.

0.023±0.005

(0.60±0.15)

0.16 (4.00)

0.22 (5.50)

0.43

(10.95)

0.51

(12.95)

0.15

(3.80)

0.62 (15.70)

Tube length: 18.3±0.08 (465±2). Tube quantity: 50.

Tube material: Antistatic coated clear pvc.

Unless otherwise stated all dimensions in inches(mm) ±0.01 (0.25).

TECHNICAL NOTES

ISOLATION VOLTAGE

‘Hi Pot Test’, ‘Flash Tested’, ‘Withstand Volt-

age’, ‘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 compo-

nent 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 operation?”

For a part holding no speciﬁc agency approv-

als 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 bar-

rier; 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 ac-

cording 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 ma-

terials, construction and environment. This

series has toroidal isolation transformers,

with no additional insulation between pri-

mary and secondary windings of enameled

wire. While parts can be expected to with-

stand several times the stated test voltage,

the isolation capability does depend on the

wire insulation. Any material, including this

enamel (typically polyurethane) is suscep-

tible 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 test-

ing, but if it is absolutely required, that the

voltage be reduced by 20% from speciﬁed

test voltage.

This consideration equally applies to agency

recognised 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.

78253J Series

MAX253 Compatible Converter SM Transformers

Technical enquiries email: mk@murata-ps.com, tel: +44 (0)1908 615232

2018-05-11 KMP_78253JC_A04 Page 5 of 5

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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. Speciﬁcations are subject to change without

This product is subject to the following operating requirements

and the Life and Safety Critical Application Sales Policy:

Refer to: http://www.murata-ps.com/requirements/

TAPE & REEL SPECIFICATIONS

REEL OUTLINE DIMENSIONS

TAPE OUTLINE DIMENSIONS

1.20

(30.4) Max.

0.94-1.08 (23.9-27.4)

0.53 (13.50)

0.50 (12.80)

0.059 (1.50)

Min.

2.36 (60) Min.

0.80 (20.20) Min.

3.9 (100)

Min.

Leader section

15.7 (400) Min.

Goods

enclosure

section

Trailer section

6.3 (160) Min.

Ø15.039 (382) Max.

0.96 (24.4)

1.04 (26.4)

Reel quantity: 500

Unless otherwise stated all

dimensions in inches (mm) ±0.01(0.25).

* Includes ﬂange distortion at outer edge.

g Measured at hub.

0.024 (0.60) Max.

0.283 (7.20)

0.369 (9.37)

Direction of unreeling

0.069 (1.75)

0.453 (11.50)

0.157 (4.00) 0.079 (2.00)

0.472 (12.00)

Cover tape

0.059 (1.50 )

+0.004

-0.000 +0.10

-0.00

0.945 (24.00 )

+0.012

-0.004

+0.30

-0.10

78253

35JC

XYYWW

Unless otherwise stated all

dimensions in inches (mm) ±0.01(0.25).