CANDD 78250V, 78250MV, 78250M, 78250 Datasheet

78250 SERIES

Converter Transformers

SELECTION GUIDE 78250/78250M

Parameter Conditions MIN TYP MAX Units

FEATURES

■ Maxim Compatible

■ Isolation to 4kV

■ Surface Mount Options

■ Toroidal Construction

■ Standard Pinout

■ UL 94V-0 Package Material

■ Fully Encapsulated

■ Low Profile

■ Industrial Temperature Range

DESCRIPTION

The 78250 series of converter transformers
are specifically designed for use with Maxim
chipsets to provide isolated RS232 interfaces.
Carefully controlled turns ratios ensure
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.

Primary Inductance, L

Leakage Inductance, L

P

L

Interwinding Capacitance, C

D.C. Resistance, R

Volt-time Product, E

DC

T

10kHz, 100mV 1.0 2.0 2.5 mH

100kHz, 100mV 2.0 3.0 µH

100kHz, 100mV 69 90 pF

WW

<0.1VDC 1.0 2.0 Ω

5kHz, 5V 50 Vµs

SELECTION GUIDE 78250V/78250MV

Parameter Conditions MIN TYP MAX Units

Primary Inductance, L

Leakage Inductance, L

P

L

Interwinding Capacitance, C

D.C. Resistance, R

Volt-time Product, E

DC

T

10kHz, 100mV 1.0 2.0 2.5 mH

100kHz, 100mV 35 40 µH

100kHz, 100mV 9 12 pF

WW

<0.1VDC 1.4 1.8 Ω

5kHz, 5V 50 Vµs

ABSOLUTE MAXIMUM RATINGS

Operating free air temperature range –40°C to 85°C
Storage temperature range –50°C to 125°C
Lead Temperature 1.5mm from case for 10 seconds 300°C
Peak current I

PK

Isolation voltage 78250(M) (flash tested for 1 second) 1500Vrms
Isolation voltage 78250V(M) (flash tested for 1 second) 4000Vrms

All specifications typical at TA= 2 5 ° C .

300mA

www.dc-dc.com

78250 SERIES

Converter Transformers

MECHANICAL DIMENSIONS

6 Pin DIP

6 Pin SM

8.89 max

6.35

3.44±0.50

0.30

0.20

9.52 max

78250

XYYWW

10.16 2.54

12.70

Top View

Primary Secondary

1

2

3

0.63

0.53

6

4

9.52 max Top View

8.89 max

78250M

XYYWW

6.35

0.30

0.20

0.90

* Pin 5 is connected to secondary centre tap.

All dimensions in mm XX.XX ±0.25mm. All pins on a 2.54mm pitch and within ±0.25mm of true position.

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 78250.2

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

C&D Technologies (NCL) Ltd

Tanners Drive, Blakelands North
Milton Keynes MK14 5BU, England
Tel: [phone]
Fax:[phone]
email: [e-mail]

www: http://www.dc-dc.com

Primary Secondary

1

2

3

2.54

6

5*

4

0.63

0.53

C&D Technologies (NCL), Inc.

8917 Glenwood Avenue, Raleigh
NC 27612, USA
Tel: [phone]
Fax: [phone]
email: [e-mail]