Finisar
Product Specification
1000BASE-T Copper SFP Transceiver
FCMJ-8520/8521-3
Product Features
•
•
•
•
•
•
•
•
Up to 1.25Gb/s bi-directional data links
Hot-pluggable SFP footprint
Extended case temperature
range (0°C to +85°C )
Fully metallic enclosure for low EMI
Low power dissipation (1.05 W typical)
Compact RJ-45 connector assembly
Access to physical layer IC via 2-wire
serial bus
10/100/1000 BASE-T operation in host
systems with SGMII interface
Applications
•
1.25 Gigabit Ethernet over Cat
5 cable
Finisar’s FCMJ-8520/8521-3 1000BASE-T Copper Small Form Pluggable (SFP)
transceivers are based on the SFP Multi Source Agreement (MSA)
1
. They are compatible
with the Gigabit Ethernet and 1000BASE-T standards as specified in IEEE Std 802.3
2
.
The 1000BASE-T physical layer IC (PHY) can be accessed via I2C, allowing access to
all PHY settings and features.
The FCMJ-8520-3 uses the SFP’s RX_LOS pin for link indication, and 1000BASE-X
auto-negotiation should be disabled on the host system. The FCMJ-8521-3 is compatible
with 1000BASE-X auto-negotiation, but does not have a link indication feature
(RX_LOS is internally grounded). See AN-2036, “Frequently Asked Questions
Regarding Finisar’s 1000BASE-T SFPs”, for a more complete explanation on the
differences between the two models and details on applications issues for the products.
PRODUCT SELECTION
Part Number
FCMJ-8520-3
FCMJ-8521-3
Link Indicator on RX_LOS Pin
Yes
No
1000BASE-X auto-negotiation
enabled by default
No
Yes
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Finisar Corporation March 16, 2005 Rev H
FINISAR [ FINISAR CORPORATION. ]
