KMP_7625XENC_B03 Page 1 of 4

www.murata-ps.com

76250ENC, 76253/XXENC

EN Approved MAX250/251/253 Compatible Converter Transformers

For full details go to

www.murata-ps.com/rohs

FEATURES

RoHS compliant

Maxim MAX250/MAX251/MAX253

compatible

BS EN 60950 approved

Toroidal construction

Industry-standard pinout

UL 94 V-0 package materials

Fully encapsulated

Compatible with RoHS soldering systems

Backward compatible with

Sn/Pb soldering systems

DESCRIPTION

The 76250ENC 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/XXENC converter transformers are

specifically designed for use with the MAX253

chip set 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 bridge or

voltage doubling.

The devices are fully approved to BS EN 60950 for

use in telecoms applications.

SELECTION GUIDE

Order Code

Input Voltage

Output

Voltage

Max. Output

Current

Isolation

Voltage

Turns

Ratio

V

V

mA

76250ENC

-

-

-

6000

1CT:1

76253/35ENC

3.3

5.0

100

6000

1:√5

76253/55ENC

5.0

5.0

200

6000

1:1.33

76250ENC CHARACTERISTICS

Parameter

Conditions

Min.

Typ.

Max.

Units

Primary Inductance, L

P

(1&5)

10kHz, 100mV

1.0

2.0

2.5

mH

Leakage Inductance, L

L

100kHz, 100mV

35

40

μH

Interwinding Capacitance, C

WW

(1&2)

100kHz, 100mV

1.5

3.0

pF

D.C. Resistance, R

DC

(1&5)

1.0

2.0

Ω

Volt-time Product, E

T

(1&5)

50

Vμs

76253/35ENC CHARACTERISTICS

Parameter

Conditions

Min.

Typ.

Max.

Units

Primary Inductance, L

P

(1&5)

100kHz, 250mV

140

200

μH

Secondary Inductance, L

S

(2&6)

100kHz, 250mV

700

1000

μH

Leakage Inductance, L

L

100kHz, 250mV

5.0

7.0

μH

Interwinding Capacitance, C

WW

(1&2)

100kHz, 250mV

2.7

3.5

pF

D.C. Resistance, R

DC

(1&5)

0.4

0.8

Ω

Volt-time Product, E

T

(1&5)

25

35

Vμs

76253/55ENC CHARACTERISTICS

Parameter

Conditions

Min.

Typ.

Max.

Units

Primary Inductance, L

P

(1&5)

100kHz, 250mV

80

150

μH

Secondary Inductance, L

S

(2&6)

100kHz, 250mV

142

267

μH

Leakage Inductance, L

L

100kHz, 250mV

7.0

10.0

μH

Interwinding Capacitance, C

WW

(1&2)

100kHz, 250mV

2.7

3.5

pF

D.C. Resistance, R

DC

(1&5)

0.5

0.9

Ω

Volt-time Product, E

T

(1&5)

30

40

Vμs

ABSOLUTE MAXIMUM RATINGS

Operating free air temperature range 76250EN

0°C to 70°C

Operating free air temperature range 76253/XXEN

-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

76250EN

300mA

Peak current, I

PK

76253/XXEN

400mA

Isolation voltage (flash tested for 1 second)

Peak wave solder temperature

300˚C for 10 seconds

Pin finish

Matte tin

All specifications typical at T

A

=25°C

1 Refer to mechanical dimensions for pin locations shown in brackets.

2 With pins 2 & 6 short circuited.