78250 SERIES
Converter Transformers
SELECTION GUIDE 78250/78250M
Parameter
Conditions
MIN
TYP
MAX
Units
Primary Inductance, L
P
Leakage Inductance, L
L
Interwinding Capacitance, C
WW
D.C. Resistance, R
DC
10kHz, 100mV
100kHz, 100mV
100kHz, 100mV
<0.1VDC
5kHz, 5V
1.0
2.0
2.0
69
1.0
2.5
3.0
90
2.0
mH
µH
pF
Ω
Vµs
FEATURES
s
Maxim Compatible
s
Isolation to 4kV
s
Surface Mount Options
s
Toroidal Construction
s
Standard Pinout
s
UL 94V-0 Package Material
s
Fully Encapsulated
s
Low Profile
s
Industrial Temperature Range
Volt-time Product, E
T
50
SELECTION GUIDE 78250V/78250MV
Parameter
Conditions
MIN
TYP
MAX
Units
Primary Inductance, L
P
Leakage Inductance, L
L
Interwinding Capacitance, C
WW
D.C. Resistance, R
DC
10kHz, 100mV
100kHz, 100mV
100kHz, 100mV
<0.1VDC
5kHz, 5V
1.0
2.0
35
9
1.4
2.5
40
12
1.8
mH
µH
pF
Ω
Vµs
DESCRIPTION
The 78250 series of converter transformers
are specifically designed for use with Maxim
chipsets to provide isolated RS232 interfaces.
Carefully controlled turns ratios ensur e
consistent performance whilst a toroidal
construction minimises EMI. The surface
mount devices are fully compatible with
CECC00802 to 280°C which allows them to
be placed and reflowed with IC’s thus
reducing time and cost in production.
Volt-time Product, E
T
50
ABSOLUTE MAXIMUM RATINGS
Operating free air temperature range
Storage temperature range
Lead Temperature 1.5mm from case for 10 seconds
Peak current I
PK
Isolation voltage 78250(M) (flash tested for 1 second)
Isolation voltage 78250V(M) (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
1500Vrms
4000Vrms
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