SLXT970AQC.B11-831643 Cortina Systems Inc, SLXT970AQC.B11-831643 Datasheet - Page 19

• Manufacturer Part Number: SLXT970AQC.B11-831643
• Manufacturer: Cortina Systems Inc

Specifications of SLXT970AQC.B11-831643

• Number Of Receivers: 1
• Data Rate: 10/100Mbps
• Operating Supply Voltage (typ): 5V
• Operating Temperature Classification: Commercial
• Operating Supply Voltage (max): 5.25V
• Operating Supply Voltage (min): 4.75V
• Mounting: Surface Mount
• Pin Count: 64
• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Lead Free Status / RoHS Status: Not Compliant

2.2
2.2.1
2.2.2
Datasheet
Interfaces (Network Media/Protocol Support)
The LXT970A Transceiver provides the following interfaces:
Twisted-Pair Interface
The Twisted-Pair Interface directly supports both 100BASE-TX and 10BASE-T applications. The
interface is capable of directly driving an RJ-45 interface through magnetics and termination
resistors. The interface uses two signal pairs - one for transmit and one for receive. A third output,
TREF, connects to the center-tap of the transmit transformer. The same signal pairs, magnetics, and
termination resistors are used for both 10 and 100 Mbps operation.
When the LXT970A Transceiver is operating as a 100 Mbps device, it transmits and receives a 125
Mbps, 5B-encoded, scrambled MLT-3 waveform on this interface. The MLT-3 waveform is
continuous. When there is no data to send, “IDLE” symbols are sent and received.
When the LXT970A Transceiver is operating as a 10 Mbps device, it transmits and receives 10
Mbps Manchester-encoded data. The waveform is not continuous. When there is no data to send,
the line is left in an idle state. Link pulses are transmitted periodically to keep the link up.
The LXT970A Transceiver supports both fixed operation and auto-negotiation with parallel
detection on this interface. Fixed operation allows the designer to specify the line speed and
duplex mode. With auto-negotiation enabled, the LXT970A Transceiver automatically determines
line speed and duplex state by exchanging capability “pages” with its link partner.
A 4 kΩ passive load is always present across the twisted-pair inputs. When enabled, the twisted-
pair inputs are actively biased to approximately 2.8V.
In applications where the Twisted-Pair Interface is not used, the inputs and outputs may be left
unconnected.
The Twisted-Pair Interface is disabled in power down mode, when the Fiber Interface is selected,
or when the transmit disconnect (bit 19.0) is set. When the Twisted-Pair Interface is disabled its
outputs are tri-stated and inputs are unbiased.
Fiber Interface
The pseudo-ECL Fiber Interface is suitable for driving 100BASE-FX applications through an
external fiber transceiver. This interface consists of a transmit and receive pair. The
LXT970A Transceiver sends and receives a continuous 125 Mbps, 5B-encoded NRZI stream on
this interface. Scrambling and MLT-3 are not used in fiber connections.
There is no industry standard for auto-negotiation on 100BASE-FX. The LXT970A Transceiver
only supports forced operation on the Fiber Interface. The LXT970A Transceiver does not support
10FL (10 Mbps fiber) applications.
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A Twisted-Pair Interface which directly supports 100BASE-TX and 10BASE-T applications.
A pseudo-ECL (PECL) Fiber Interface which supports 100BASE-FX applications through an
external fiber transceiver.
An MII (Media Independent Interface) for interfacing 10/100 Media Access Controllers
(MACs).
A Hardware Control Interface to configure various operating characteristics.
Intel
®
LXT970A Dual-Speed Fast Ethernet Transceiver
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