Data Sheet
MARCH 2000
Revision 1.4
LXT901A/907A
Universal 3.3V Ethernet Transceiver
General Description
Features
Functional Features
The LXT901A and LXT907A are new generation
Universal Ethernet Transceivers with improved noise
immunity and output filtering. The feature set of the
LXT901A/907A has been streamlined, removing Remote
Signaling capabilities. The LXT901A and LXT907A
provide all the active circuitry to interface most standard
802.3 controllers to either the 10BASE-T media or
Attachment Unit Interface (AUI).
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Integrated Filters - Simplify FCC Compliance
Integrated Manchester Encoder/Decoder
10BASE-T Transceiver
AUI Transceiver
Full-Duplex Capable (20 Mbps)
Convenience Features
The LXT901A and LXT907A are identical except for the
function of one pin. The LXT901A, with selectable
termination impedance allows the use of either shielded or
unshielded twisted-pair cable. The LXT907A offers a
Signal Quality Error disable (DSQE) function.
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LXT901A and LXT907A functions include Manchester
encoding/decoding, receiver squelch and transmit pulse
shaping, jabber, link testing and reversed polarity
detection/correction.
Automatic/Manual AUI/RJ-45 Selection
Automatic Polarity Correction
SQE Disable function (LXT907A)
Programmable Impedance Driver (LXT901A)
Single 3.3V operation
Power Down Mode and four loopback modes
Available in 64-pin LQFP and 44-pin PLCC packages
• Commercial (0 to +70oC)
Applications
Diagnostic Features
• Four LED Drivers
• 10BASE-T hub and switching products
• AUI/RJ-45 Loopback
• Computer/workstation 10BASE-T LAN adapter boards
LXT901A/907A Block Diagram
MD0
AUTOSEL
MODE SELECT LOGIC
Controller Compatibility
Port Select
Loopback
Link test
PAUI
LBK
LI
MD1
TCLK
CLKI
WATCHDOG
TIMER
XTAL
OSC
CLKO
TEN
TWISTED PAIR
INTERFACE
Select:
PLS Only
or
PLS / MAU
TXD
CMOS
TX
AMP
PULSE SHAPER
AND FILTER
TPOPB
TPOPA
TPONA
TPONB
RC
DO
COLLISION/
POLARITY
DETECT
CORRECT
MANCHESTER
ENCODER
STP
(LXT901A only)
RC
RX
SLICER
TPIP
TPIN
DROP CABLE
INTERFACE
ECL
TX
AMP
SQUELCH / LINK
DETECT
CD
LEDL
+
DOP
-
DON
LPBK
RXD
DI
MANCHESTER
DECODER
RCLK
DIN
CI
COLLISION LOGIC
COL
LEDR LEDT/PDN
LEDC/FDE
DSQE
DIP
RX SLICER
NTH JAB
COLLISION
RECEIVER
CIP
CIN
PLR
(LXT907A only)
Refer to www.level1.com for most current information.
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