78253/35C Murata Power Solutions Inc, 78253/35C Datasheet - Page 4

• Manufacturer Part Number: 78253/35C
• Description: Transformers MAX253 CNVR XFRMR 3.3Vin 5Vout 1500VDC
• Manufacturer: Murata Power Solutions Inc
• Type: Compatible Converter Transformersr

Specifications of 78253/35C

• Power Rating: 500 mW
• Primary Voltage Rating: 3.3 V
• Secondary Voltage Rating: 5 V
• Mounting Style: Through Hole
• Dimensions: 9.52 mm L x 8.89 mm W x 6.35 mm H
• Product: Toroidal Power Transformers
• Height: 6.35 mm
• Length: 9.52 mm
• Number Of Outputs: 2
• Operating Temperature Range: - 40 C to + 85 C
• Secondary Resistance: 0.4 Ohms
• Termination Style: Through Hole
• Turns Ratio: 1:5
• Width: 8.89 mm
• Primary Voltages: 5V
• Current Rating: 100mA
• Transformer Mounting: Through Hole
• Isolation Voltage: 1500VDC
• Peak Reflow Compatible (260 C): Yes
• Transformer Type: Pulse
• Supply Voltage: 3.3V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

TECHNICAL NOTES
ISOLATION
‘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 specifi ed 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 specifi c 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.
TYPICAL CHARACTERISTICS (VOLTAGE CURVES) continued
www.murata-ps.com
VOLTAGE
110
105
100
110
105
100
90
95
90
95
-50
-50
-25
-25
Temperature (°C)
Temperature (°C)
0
78253/35(M)VC
0
78253/35(M)C
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 specifi ed
test voltage.
This consideration equally applies to agency
recognized 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.
25
25
50
50
75
75
100
100
VOLTAGE DEVIATION
All specifi cations typical at T
1 For further information, please visit www.murata-ps.com/rohs
SOLDERING INFORMATION
110
105
100
Pin fi nish
Peak wave solder temperature
Peak refl ow temperature
110
105
100
TUBE OUTLINE DIMENSIONS
95
90
95
90
-50
-50
0.023±0.005
(0.60±0.15)
Technical enquiries - email: [e-mail], tel:
-25
-25
0.22 (5.50)
0.16 (4.00)
MAX253 Compatible Converter Transformers
Temperature (°C)
Temperature (°C)
0
78253/55(M)C
78253/55(M)VC
0
A
Unless otherwise stated all dimensions in inches(mm) ±0.01 (0.25).
=25°C
25
25
1
50
50
0.62 (15.70)
Tube length: 18.3±0.08 (465±2). Tube quantity: 50.
(10.95)
(3.80)
0.43
0.15
78253 Series
75
75
Tube material: Antistatic coated clear pvc.
KMP_78253C_C03 Page 4 of 5
100
100
Matte tin
300˚C for 10 seconds
220˚C
[phone]
(12.95)
0.51