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
capable of accepting input signals as low as 2mV
P-P
with a
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)
Incorporates an AU interface
Highly stable data quantizer with 55dB input
dynamic range
Input sensitivity as low as 2mV
P-P
Up to 100mA maximum current driven fiber optic LED
driver for accurate launch power
Single +5 volt supply
No crystal or clock required
Five network status LED outputs
BLOCK DIAGRAM
SQEN/JABD
5
+5V
V
CC
Tx
(+5V)
17
RTSET
12
GND
20
AV
CC
27
Tx+
10
Tx–
11
AUI
RECEIVER
FIBER OPTIC
LED
DRIVER
18
TxOUT
15
XMT
Tx
SQUELCH
1MHz IDLE
SIGNAL
JABBER
LED
DRIVERS
16
RCV
1
CLSN
28
JAB
SQE
BIAS
COL+
2
COL–
3
RECEIVE SQUELCH
AUI
DRIVER
10MHz GATED
OSCILLATOR
14
LMON
AMP
Tx
Rx+
6
Rx–
7
AUI
DRIVER
LOOPBACK
MUX
Rx
26
V +
IN
25
V
IN
–
CMP
∫
V
REF
LINK DETECT
19
9
13
8
24
4
21
V
DC
22
V
REF
23
V
THADJ
GND
V
CC
(+5V)
RRSET LBDIS
+5V
AGND
C
TIMER
1
MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
