78253J Series
MAX253 Compatible Converter SM Transformers
SELECTION GUIDE
Output
Voltage
Max. Output
Current
Isolation
Voltage
Input Voltage
Turns
Ratio
Order Code
V
V
mA
100
200
100
200
VDC
78253/35JC
78253/55JC
78253/35JVC
78253/55JVC
3.3
5.0
3.3
5.0
5.0
5.0
5.0
5.0
1500
1500
4000
4000
1:2.27
1:1.31
1:2.14
1:1.33
ORDER CODE DETAILS
Order Code
FEATURES
nJ-STD-020D reflow
Package Type
Packaging Type
Tube
Quantity
78253/XXJ(V)C
78253/XXJ(V)C-R
6 Pin SM
6 Pin SM
50
Tape & Reel
500
nRoHS compliant
78253/35JC CHARACTERISTICS
Parameter
Primary Inductance, LP
nMaxim MAX253 compatible
n3.3V and 5V versions
nIsolation to 4kVDC
Conditions
Min.
0.27
1.60
Typ.
0.36
2.00
0.32
24
Max.
Units
mH
mH
μH
100kHz, 250mV
100kHz, 250mV
100kHz, 250mV
100kHz, 250mV
>0.1VDC
0.50
2.40
1.00
50
Secondary Inductance, LS
Leakage Inductance, LL
Interwinding Capacitance, CWW
Primary D.C. Resistance, RDC
Volt-time Product, Et
nFrequency range to 500kHz
nToroidal construction
nIndustry-standard pinout
nUL 94 V-0 package materials
nLow profile
pF
0.5
1.00
Ω
Vμs
Pins 1/2 or 2/3
30
49
78253/55JC CHARACTERISTICS
Parameter
Primary Inductance, LP
Conditions
Min.
0.57
1.10
Typ.
0.83
1.40
0.51
30
Max.
1.10
1.70
1.00
50
Units
mH
mH
μH
100kHz, 250mV
100kHz, 250mV
100kHz, 250mV
100kHz, 250mV
>0.1VDC
Secondary Inductance, LS
Leakage Inductance, LL
Interwinding Capacitance, CWW
Primary D.C. Resistance, RDC
Volt-time Product, Et
nIndustrial temperature range
pF
DESCRIPTION
0.70
70
1.50
Ω
Vμs
Pins 1/2 or 2/3
40
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.
78253/35JVC CHARACTERISTICS
Parameter
Conditions
Min.
110
550
Typ.
142
710
3.46
2
Max.
203
Units
μH
Primary Inductance, LP
Secondary Inductance, LS
Leakage Inductance, LL
Interwinding Capacitance, CWW
Primary D.C. Resistance, RDC
Volt-time Product, Et
100kHz, 20mV
100kHz, 20mV
100kHz, 250mV
100kHz, 250mV
>0.1VDC
850
μH
5.00
8.00
0.50
μH
pF
For through hole versions see 78253 series
datasheet.
0.30
30
Ω
Vμs
Pins 1/2 or 2/3
18
78253/55JVC CHARACTERISTICS
Parameter
Conditions
Min.
170
350
Typ.
240
444
6.28
3.4
Max.
335
Units
μH
Primary Inductance, LP
Secondary Inductance, LS
Leakage Inductance, LL
Interwinding Capacitance, CWW
Primary D.C. Resistance, RDC
Volt-time Product, Et
100kHz, 20mV
100kHz, 20mV
100kHz, 250mV
100kHz, 250mV
>0.1VDC
540
μH
8.00
8.00
0.60
μH
pF
0.40
37
Ω
Vμs
Pins 1/2 or 2/3
25
All specifications typical at TA=25°C
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com/support
Technical enquiries email: mk@murata-ps.com, tel: +44 (0)1908 615232
2014-06-10 KMP_78253JC_A03 Page 1 of 5