March 1997

ML4668

Low Power Single Chip 10BASE-FL Transceiver

GENERAL DESCRIPTION

The ML4668 single-chip 10BASE-FL transceiver is a low

power, high output current, plug-compatible version of the

industry standard ML4663. The ML4668 offers a standard

IEEE 802.3 AU interface that allows it to be directly

connected to industry standard manchester encoder/

decoder chips or an AUI connector.

The ML4668 provides a highly integrated solution that

requires a minimal number of external components, and is

compliant to the IEEE 802.3 10BASE-FL standard. The

transmitter offers a 100mA maximum current drive output

that directly drives a fiber optic LED transmitter. The

receiver offers a highly stable fiber optic data quantizer

55dB dynamic range.

The transmitter automatically inserts 1MHz signal during

idle time and removes this signal on reception. Low Light is

continuously monitored for both activity as well as power

level. Five LED status indicators monitor error conditions as

well as transmissions, receptions and collisions.

FEATURES

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Single chip solution for 10BASE-FL internal or external

Medium Attachment Units (MAUs)

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Incorporates an AU interface

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Highly stable data quantizer with 55dB input

dynamic range

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Up to 100mA maximum current driven fiber optic LED

driver for accurate launch power

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Single +5 volt supply

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No crystal or clock required

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Five network status LED outputs

BLOCK DIAGRAM

1

AUI

RECEIVER

Tx

SQUELCH

AUI

DRIVER

AUI

DRIVER

10MHz GATED

OSCILLATOR

LOOPBACK

MUX

JABBER

RECEIVE SQUELCH

LINK DETECT

LED

DRIVERS

FIBER OPTIC

LED

DRIVER

1MHz IDLE

SIGNAL

SQE

GND

(+5V)

+5V

LBDIS

AGND

RRSET

Tx

Rx

BIAS

GND

(+5V)

+5V

RTSET

SQEN/JABD

Tx+

Tx–

COL+

COL–

Rx+

Rx–

TxOUT

∫

CMP

AMP

LMON

14

JAB

28

CLSN

1

RCV

16

XMT

15

18

27

20

12

17

5

10

11

2

3

6

7

19

9

13

8

24

4

23

22

21

25

26