ML6673 Datasheet, PDF (1/8 Pages) Micro Linear Corporation – Fast Ethernet/FDDI TP-PMD Transceiver

December 1998
ML6673
Fast Ethernet/FDDI TP-PMD Transceiver
GENERAL DESCRIPTION
The ML6673 is a complete monolithic transceiver for 125
Mbaud MLT-3 encoded data transmission over Category 5
unshielded twisted pair and shielded twisted pair cables.
The ML6673 integrates the baseline restoration function
defined in the TP-PMD standard. The adaptive equalizer in
the ML6673 will accurately compensate for line losses
exceeding the IEEE 802.3u limit of 100m of UTP.
The ML6673 receive section consists of an equalizing filter
with a feedback loop for controlling effective line
compensation. The feedback loop contains a filter and
detection block for determining the proper control signal.
The ML6673 also contains data comparators with
precisely controlled slicing thresholds and an MLT-3 to
NRZI translator.
The ML6673 transmit section accepts ECL 100K
compatible NRZ inputs and converts them to differential
current mode MLT-3 signals. Transmit amplitude is
controlled by a single external resistor.
FEATURES
s Compliant with IEEE 802.3u Fast Ethernet (100BASE-TX)
standard
s Compliant with ANSI X3T12 FDDI over copper
(TP-PMD) standard
s Integrated baseline wander correction circuit
s Transmitter converts NRZI ECL signals to MLT-3 current
driven outputs
s Transmitter can be externally turned off
(high impedence) for true quiet line
s Receiver includes adaptive equalizer and MLT-3 to
NRZI decoder
s Operates over 100 meters of STP or category 5 UTP
Twisted Pair Cable set by the IEEE 802.3u standards
s 32-pin PLCC and TQFP
BLOCK DIAGRAM
TXIN+
TXIN–
SD+
SD–
RXOUT+
RXOUT–
LPBK
TXOFF
NRZI
TO MLT-3
LINK
STATUS
MUX
MLT-3
TO NRZI
TVCCA
TVCCD
RTSET
RTSET1
RTSET2
BASELINE
WANDER
CORRECTION
ADAPTIVE
CONTROL
ADAPTIVE
EQUALIZER
TPOUT+
TPOUT–
TPIN+
TPIN–
TGNDA TGNDD
GND
RRSET1
RRSET2
RRSET RVCCA RVCCD CMREF
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