FEATURES
s
Maxim Compatible
s
BS EN 60950 Approved
s
Isolation to 6kV
s
Toroidal Construction
s
Industry Standard Pinout
s
UL 94V-0 Package Material
s
Fully Encapsulated
DESCRIPTION
The 76250EN converter transformer is
specifically designed for use with Maxim
chipsets to provide isolated RS232 interfaces.
A carefully controlled turns ratio ensures
consistent performance whilst a toroidal
construction minimises EMI.
The 76253/XXEN converter transformers
are specifically designed for use with the
MAX253 chipset to provide isolated power
supplies. The 5V version can supply 1W
and the 3.3V version can supply 500mW.
A centre tapped secondary winding allows
for full bridge, half bride or voltage doubling.
The devices are fully approved to BS EN
60950 for use in telecoms applications.
76250EN CHARACTERISTICS
Parameter
Conditions
MIN
TYP
MAX
Units
Primary Inductance, L
P
10kHz, 100mV
1.0
2.0
2.5
mH
Leakage Inductance, L
L
100kHz, 100mV
35
40
H
Interwinding Capacitance, C
WW
100kHz, 100mV
5.0
10
pF
D.C. Resistance, R
DC
<0.1VDC
1.0
2.0
Volt-time Product, E
T
5kHz, 5V
50
Vs
76253/35EN CHARACTERISTICS
Parameter
Conditions
MIN
TYP
MAX
Units
Primary Inductance, L
P
100kHz, 250mV
53
92
120
H
Secondary Inductance, L
S
100kHz, 250mV
350
460
600
H
Leakage Inductance, L
L
100kHz, 250mV
1.5
3.6
H
Interwinding Capacitance, C
WW
100kHz, 250mV
1.80
3.00
pF
D.C. Resistance, R
DC
>0.1VDC
0.60
1.00
Volt-time Product, E
T
5kHz, 5V
20
35
Vs
76253/55EN CHARACTERISTICS
Parameter
Conditions
MIN
TYP
MAX
Units
Primary Inductance, L
P
100kHz, 250mV
120
205
250
H
Secondary Inductance, L
S
100kHz, 250mV
280
362
445
H
Leakage Inductance, L
L
100kHz, 250mV
3.90
5.00
H
Interwinding Capacitance, C
WW
100kHz, 250mV
1.20
3.00
pF
D.C. Resistance, R
DC
>0.1VDC
0.90
1.50
Volt-time Product, E
T
5kHz, 5V
20
23
Vs
ABSOLUTE MAXIMUM RATINGS
All specifications typical at T
A
= 2 5 C .
SELECTION GUIDE
Input
Output
Output
Isolation
Turns
Voltage
Voltage
Current
Voltage
Ratio
Order Code
(V)
(V)
(mA Max)
(VDC)
76250EN
6000
1CT:1
76253/35EN
3.3
5.0
100
6000
1:
5
76253/55EN
5.0
5.0
200
6000
1:1.33
Operating free air temperature range 76250EN
0C to 70C
Operating free air temperature range 76253/XXEN
40C to 85C
Storage temperature range
50C to 125C
Lead Temperature 1.5mm from case for 10 seconds
300C
Peak current I
PK
76250EN
300mA
Peak current I
PK
76253/XXEN
400mA
Isolation voltage (flash tested for 1 second)
6000VDC
76250EN, 76253/XXEN
EN Approved Converter Transformers
www.dc-dc.com
76250EN, 76253/XXEN
EN Approved Converter Transformers
C&D Technologies (NCL) Ltd
Tanners Drive, Blakelands North
Milton Keynes MK14 5BU, England
Tel: +44 (0)1908 615232
Fax:+44 (0)1908 617545
email: info@cdtechno-ncl.com
www: http://www.dc-dc.com
C&D Technologies (NCL), Inc.
8917 Glenwood Avenue, Raleigh
NC 27612, USA
Tel: +1 (919) 571-9405
Fax: +1 (919) 571-9262
email: info@us.cdtechno-ncl.com
C&D Technologies (NCL) Limited reserve the right to alter or improve the
specification, internal design or manufacturing process at any time, without
notice. Please check with your supplier or visit our web site to ensure that
you have the current and complete specification for your product before use.
C&D Technologies (NCL) Limited 2000
NMP 7625XEN.2
No part of this publication may be copied, transmitted or stored in a
retrieval system or reproduced in any way including, but not limited to,
photography, photocopy, magnetic or other recording means, without prior
written permission from C&D Technologies (NCL) Limited.
Instructions for use are available from www.dc-dc.com
0
20
40
60
80
100
Output Current (mA)
FS=High
FS=Low
76253/35EN
EFFICIENCY CURVES
0
100
200
300
400
Output Current (mA)
FS=High
FS=Low
76253/55EN
100
80
60
40
20
0
-50
-25
0
25
50
75
100
Temperature (C)
FS=High
FS=Low
76253/35EN
VOLTAGE DEVIATION
1 1 0
105
100
9 5
9 0
-50
-25
0
25
50
75
100
Temperature (C)
FS=High
FS=Low
76253/55EN
1 1 0
105
100
9 5
9 0
MECHANICAL DIMENSIONS
TYPICAL CHARACTERISTICS
* 76250EN Pin not fitted.
All dimensions in mm XX.XX 0.25mm. All pins on a 2.54mm pitch and within 0.25mm of true position.
76250EN
YYWW
15.00
15.00
1
3
5
2
4*
6
12.50
4.10
12.00
2.54
7.50
0.56 0.05
0
20
40
60
80
100
Output Current (mA)
FS=High
FS=Low
76253/35EN
VOLTAGE CURVES
10
8
6
4
2
0
0
100
200
300
400
Output Current (mA)
FS=Low/High
76253/55EN
10
8
6
4
2
0
10.16
2.42
Primary
Pin Connections 76250EN (Top View)
1
3
5
2
6
Secondary
Primary
Pin Connections 76253/XXEN (Top View)
1
3
5
2
4
6
Secondary
100
80
60
40
20
0
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