WJLXT971ALE.A4 Cortina Systems Inc, WJLXT971ALE.A4 Datasheet - Page 57

• Manufacturer Part Number: WJLXT971ALE.A4
• Manufacturer: Cortina Systems Inc

Specifications of WJLXT971ALE.A4

• Lead Free Status / RoHS Status: Compliant

LXT971A PHY
Datasheet
249414, Revision 5.2
13 September 2007
Figure 24
6.3
Cortina Systems
Figure 24
Typical Media Independent Interface
Fiber Interface
The fiber interface consists of an LVPECL transmit and receive pair to an external
fiber-optic PHY. Both 3.3 V fiber-optic PHYs and 5 V fiber-optic PHYs can be used with
the LXT971A PHY. For details on fiber interface designs and recommendations for
Cortina PHYs, see the document on 100BASE-FX fiber optics listed in
Related
As shown in
Figure 25
fiber PHY.
®
• The transmit pair should be DC-coupled with the 50 Ω/16 Ω pull-up combination.
• The transmit pair should have a 2.74 kΩ pull-down resistor to prevent PHY-to-fiber
• The receive pair should be DC-coupled with an emitter current path for the fiber PHY.
• The signal detect pin should be DC-coupled with an emitter current path for the fiber
LXT971A Single-Port 10/100 Mbps PHY Transceiver
PHY crosstalk amplification in power-down, loopback, and reset states. (See the fiber
interface application note.)
PHY.
Documents.
shows a typical example of an interface between the LXT971A PHY and a 3.3 V
show a typical media independent interface (MII) for the LXT971A PHY.
Figure
MAC
25, the following should occur in 3.3 V fiber PHY applications:
TX_CLK
TXD[3:0]
RX_CLK
RX_DV
RX_ER
TX_EN
TX_ER
CRS
COL
RXD[3:0]
LXT97x
PHY
former
Trans-
Section 1.2,
6.3 Fiber Interface
B3400-03
RJ-45
Page 57