www.murata-ps.com
78250J Series
MAX250/MAX251 Compatible Converter SM Transformers
CHARACTERISTICS 78250JC
Parameter
Primary Inductance, L
P
Leakage Inductance, L
L
Interwinding Capacitance, C
WW
Primary D.C. Resistance, R
DC
Volt-time Product, Et
Turns Ratio
Conditions
10kHz, 100mV
100kHz, 100mV
100kHz, 100mV
<0.1VDC
Pins1/2 or 2/3
Min.
1.0
Typ.
2.0
0.6
48
0.7
1:1
Max.
2.5
3.0
90
2.0
Units
mH
μH
pF
Ω
Vμs
50
FEATURES
J-STD-020D reflow
RoHS compliant
Maxim MAX250/MAX251 compatible
Isolation to 4kVrms
Industry-standard pinout
Surface mount option
UL 94 V-0 package materials
Low profile
Toroidal construction
Industrial temperature range
ABSOLUTE MAXIMUM RATINGS
CHARACTERISTICS 78250JVC
Parameter
Primary Inductance, L
P
Leakage Inductance, L
L
Interwinding Capacitance, C
WW
Primary D.C. Resistance, R
DC
Volt-time Product, Et
Turns Ratio
Conditions
10kHz, 100mV
100kHz, 100mV
100kHz, 100mV
<0.1VDC
Pins1/2 or 2/3
Min.
1.0
Typ.
2.0
35
4
0.9
1:1
Max.
2.5
40
10
1.8
Units
mH
μH
pF
Ω
Vμs
50
ORDER CODE DETAILS
Order Code
78250JC / 78250JVC
78250JC-R / 78250JVC-R
Package Type
6 Pin SM
6 Pin SM
Packaging Type
Tube
Tape & Reel
Quantity
50
500
DESCRIPTION
The 78250 series of converter transformers
are specifically designed for use with Maxim
chipsets to provide isolated RS232 interfaces.
Carefully controlled turns ratios ensure consistent
performance whilst a toroidal construction
minimises EMI.
For through hole versions see 78250 datasheet.
Operating free air temperature range
Storage temperature range
Lead temperature 1.5mm from case for 10 seconds
Peak current, I
PK
Isolation voltage 78250(J)C (flash tested for 1 second)
Isolation voltage 78250V(J)C (flash tested for 1 second)
All specifications typical at T
A
=25°C
-40°C to 85°C
-50°C to 125°C
300°C
300mA
1.5kVrms
4.0kVrms
TECHNICAL NOTES
ISOLATION
VOLTAGE
‘Hi Pot Test’, ‘Flash Tested’, ‘Withstand Voltage’, ‘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 component designed to provide electri-
cal 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 volt-
age that can be applied across the part in normal operation?”
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-accessi-
ble 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 depend on
the wire insulation. Any material, including this enamel
(typically polyurethane) is susceptible to eventual
chemical degradation when subject to very high ap-
plied voltages thus implying that the number of tests
should be strictly limited. We therefore 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.
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com/support
KMP_78250JC_A05
Page 1 of 3
78250J Series
MAX250/MAX251 Compatible Converter SM Transformers
PACKAGE SPECIFICATIONS
MECHANICAL DIMENSIONS
0.5
(12.70)
0.375
(9.52) Max.
Primary
Secondary
1
0.354
(9.0) Max.
6
5*
4
78250JC
XYYWW
2
3
0.25
(6.35)
0.012 (0.30)
0.008 (0.20)
0.035 (0.90)
0.1 (2.54)
0.025 (0.63)
0.021 (0.53)
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.
* Pin 5 is connected to secondary center tap. Package Weight 1.0g TYP.
RECOMMENDED FOOTPRINT DETAILS
0.06 (1.60)
0.10 (2.54)
0.04
(1.00)
0.45
(11.50)
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.
TUBE OUTLINE DIMENSIONS
0.43
(10.95)
0.16 (4.00)
0.023±0.005
(0.60±0.15)
0.51
(12.95)
Unless otherwise stated all
dimensions in inches (mm)
±0.01 (0.25).
Tube length: 18.3±0.08 (465±2).
Tube material: Antistatic coated
clear pvc.
SOLDERING INFORMATION
1
Pin finish
Max. peak reflow temperature
Moisture sensitivity level
2
Max. time above liquidous (217°C)
Matte tin
245°C
1
100s
0.22 (5.50)
0.15
(3.80)
0.62 (15.70)
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.
www.murata-ps.com/support
KMP_78250JC_A05
Page 2 of 3
78250J Series
MAX250/MAX251 Compatible Converter SM Transformers
TAPE & REEL SPECIFICATIONS
REEL OUTLINE DIMENSIONS
Ø15.039 (382) Max.
2.36 (60) Min.
0.94-1.08 (23.9-27.4)
*
Ø 0.53 (13.50)
0.50 (12.80)
Leader section
15.7 (400) Min.
3.9 (100)
Min.
0.059 (1.50)
Min.
1.20
(30.4) Max.
Goods
enclosure
section
0.96 (24.4)
1.04 (26.4)
Trailer section
6.3 (160) Min.
Unless otherwise stated all
dimensions in inches (mm) ±0.01(0.25).
* Includes flange distortion at outer edge.
Measured at hub.
Ø 0.80 (20.20) Min.
TAPE OUTLINE DIMENSIONS
0.069 (1.75)
0.157 (4.00)
0.079 (2.00)
+0.004
+0.10
0.059 -0.000 (1.50 -0.00 )
0.945
+0.012
(24.00
+0.30
)
-0.10
-0.004
0.453 (11.50)
78250JC
XYYWW
Cover tape
0.369 (9.37)
0.472 (12.00)
0.024 (0.60) Max.
Direction of unreeling
0.283 (7.20)
Unless otherwise stated all
dimensions in inches (mm) ±0.01(0.25).
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/
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
notice.
© 2018 Murata Power Solutions, Inc.
www.murata-ps.com/support
KMP_78250JC_A05
Page 3 of 3
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