78253 Series
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MAX253 Compatible Converter Transformers
SELECTION GUIDE
Output Max. Output Isolation
Input Voltage Turns Package
Order Code Voltage Current Voltage
Ratio Style
V V mA VDC
78253/35C DIL
3.3 5.0 100 1500 1:2.27
78253/35MC SM
78253/55C DIL
5.0 5.0 200 1500 1:1.31
78253/55MC SM
78253/35VC DIL
3.3 5.0 100 4000 1:2.14
78253/35MVC SM
FEATURES
78253/55VC DIL
5.0 5.0 200 4000 1:1.33
n RoHS compliant
78253/55MVC SM
n Maxim MAX253 compatible
ORDER CODE DETAILS
n 3.3V and 5V versions
Order Code Package Type Packaging Type Quantity
78253/XX(V)C 6 Pin DIL Tube 50
n Isolation to 4kVDC
78253/XXM(V)C 6 Pin SM Tube 50
n Frequency range to 500kHZ
78253/XXM(V)C-R 6 Pin SM Tape & Reel 500
n Toroidal construction
78253/35(M)C CHARACTERISTICS
Parameter Conditions Min. Typ. Max. Units
n Industry-standard pinout
Primary Inductance, L 100kHz, 250mV 0.30 0.38 0.46 mH
P
n UL 94 V-0 package materials
Secondary Inductance, L 100kHz, 250mV 1.60 2.00 2.40 mH
S
n Fully encapsulated
Leakage Inductance, L 100kHz, 250mV 0.30 1.00 H
L
Interwinding Capacitance, C 100kHz, 250mV 30 50 pF
WW
n Low profile
Primary D.C. Resistance, R >0.1VDC 0.40 1.00
DC
n Surface mount option
Volt-time Product, Et Pins 1/2 or 2/3 30 35 Vs
n Industrial temperature range
78253/55(M)C CHARACTERISTICS
Parameter Conditions Min. Typ. Max. Units
Primary Inductance, L 100kHz, 250mV 0.60 0.83 1.10 mH
P
DESCRIPTION
Secondary Inductance, L 100kHz, 250mV 1.10 1.40 1.70 mH
S
The 78253 series of converter transformers are
Leakage Inductance, L 100kHz, 250mV 0.35 1.00 H
L
specifically designed for use with the MAX253
Interwinding Capacitance, C 100kHz, 250mV 30 50 pF
WW
chip set to provide isolated power supplies. The
Primary D.C. Resistance, R >0.1VDC 0.70 1.50
DC
5V version can supply 1W and the 3.3V version
Volt-time Product, Et Pins 1/2 or 2/3 40 50 Vs
can supply 500mW. A centre tapped secondary
78253/35(M)VC CHARACTERISTICS
winding allows for full bridge, half bridge or
Parameter Conditions Min. Typ. Max. Units
voltage doubling.
Primary Inductance, L 100kHz, 20mV 110 142 185 H
P
Secondary Inductance, L 100kHz, 20mV 550 710 850 H
S
Surface-mount parts
Leakage Inductance, L 100kHz, 250mV 3.00 5.00 H
L
The surface-mount (M suffix) products are not Interwinding Capacitance, C 100kHz, 250mV 4.20 8.00 pF
WW
Primary D.C. Resistance, R >0.1VDC 0.30 0.50
recommended for new designs. For existing designs,
DC
Volt-time Product, Et Pins 1/2 or 2/3 18 22 Vs
however, Murata Power Solutions will continue to
manufacture and fully support these parts.
78253/55(M)VC CHARACTERISTICS
For recommended alternatives please refer to the
Parameter Conditions Min. Typ. Max. Units
78253J Series datasheet.
Primary Inductance, L 100kHz, 20mV 190 240 310 H
P
Secondary Inductance, L 100kHz, 20mV 350 444 540 H
S
Leakage Inductance, L 100kHz, 250mV 5.20 8.00 H
L
Interwinding Capacitance, C 100kHz, 250mV 4.20 8.00 pF
WW
Primary D.C. Resistance, R >0.1VDC 0.40 0.60
DC
Volt-time Product, Et Pins 1/2 or 2/3 25 28 Vs
All specifications typical at T =25C
A
For full details go to
For full details go towww.cd4power.com/rohs
www.murata-ps.com/rohs
www.murata-ps.com/support
KMP_78253C_D05 Page 1 of 578253 Series
MAX253 Compatible Converter Transformers
ABSOLUTE MAXIMUM RATINGS
Operating free air temperature range -40C to 85C
Storage temperature range -50C to 125C
300C
Lead Temperature 1.5mm from case for 10 seconds
400mA
Peak current I
PK
1500VDC
Isolation voltage 78253/XX(M)C (flash tested for 1 second)
Isolation voltage 78253/XX(M)VC (flash tested for 1 second) 4000VDC
PACKAGE SPECIFICATIONS
MECHANICAL DIMENSIONS
6 Pin DIL 6 Pin SM
0.5
(12.70)
0.375
0.375
(9.52) MAX (9.52) MAX
Top View Top View
Primary Secondary
Primary Secondary
1 6 1 6
0.354 0.354
2 2
5 5
(9.0) MAX
(9.0) MAX
78253/35C
78253/55MC
3 4 3 4
XYYWW
XYYWW
0.25
0.25
(6.35)
(6.35)
0.1350.02 0.012 0.30
0.035 0.025 (0.63)
(3.440.50) (0.008 0.20)
(0.90) 0.021 (0.53)
0.1
0.012(0.30) 0.025 (0.63)
(2.54)
0.008(0.20) 0.021 (0.53)
0.40
0.1 (2.54)
(10.16) 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.
RECOMMENDED FOOTPRINT DETAILS
6 Pin DIL
6 Pin SM
0.10 (2.54) 0.10 (2.54)
0.06 (1.60) 0.06 (1.60)
0.10 (2.54) 0.10 (2.54)
0.10 (2.54) 0.10 (2.54)
+0.006 (0.15)+0.006 (0.15)
0.05 (1.20) 0.05 (1.20)
-0.000 (0.00)-0.000 (0.00)
0.04 0.04
(1.00) (1.00)
0.45 0.45
(11.50) (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.
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KMP_78253C_D05 Page 2 of 5