4

EC100.H (2/05)

Typical Application Circuit

+5 V

+ 12 V

TXLED

RXLED

COLLED

POLLED

LNKLED

TXU+

TXS+

TXS-

TXU-

RXI+

RXI-

Req

Rlx

CD+

CD-

RX+

RX-

TX+

TX-

TD+

TD-

RD+

RD-

+5 V

R1 R2

R3

R4

R5

R6

R7

R8

R9

R13

R10

49.9

R11

49.9

C1

0.01 µF

C2

0.01 µF

C5

0.01

µF

R12

1:1

PE-65728

PE-68023

1:2

LED

INDICATORS

TPI

R J-45

AUI

D B15

+12 V

CD+

CD-

RX+

RX-

TX+

TX-

GND

R16

39.2

R17

39.2

R18

39.2

R19

39.2

C4

0.01 µF

C3

0.01 µF

DP83907

NOTE 2

1:1

NOTE 3

NOTE 1

NOTES:

1. Connections at pins 12 and 13 apply to PE-68023 only. These are test points. Do not ground.

2. For specific information, see pages 2 and 3 in this catalog.

3. For specific connection, refer to National’s Application Notes.

ISOLATION TRANSFORMERS