DP83257VF National Semiconductor, DP83257VF Datasheet - Page 29

• Manufacturer Part Number: DP83257VF
• Description: IC FDDI LAYER CTRLR 160PQFP
• Manufacturer: National Semiconductor

Specifications of DP83257VF

• Controller Type: physical layer controller
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 160-BFQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Supply: -
• Interface: -
• Other names: *DP83257VF

3 0 Functional Description
3 8 PMD INTERFACE
The PMD Interface connects the PLAYER
standard FDDI Physical Media Connection such as a fiber
optic transceiver or a copper twisted pair transceiver It is a
125 MHz full duplex serial connection
The DP83256 PLAYER
face This PMD Interface should be used for all PMD imple-
mentations that do not require an external scrambler
descrambler function clock recovery function or clock
generation function such as a Fiber Optic or Shielded
Twisted Pair (SDDI) PMDs
The DP83256-AP and DP83257 PLAYER
two PMD interfaces The PMD Interface should be used for
all PMD implementations that do not require an external
scrambler descrambler function clock recovery function
a
device contains one PMD inter-
FIGURE 3-20 Fiber Optic or STP PMD Connection
a
devices contain
FIGURE 3-21 UTP PMD Connections
a
(Continued)
device to a
29
Figure 3-20 shows how the DP83256 DP83256-AP or
Figure 3-21 shows how the DP83256-AP or DP83257
or clock generation function such as a Fiber Optic or
Shielded Twisted Pair (SDDI) PMDs The second Alternate
PMD Interface can be used to support Unshielded Twisted
Pair (UTP) PMDs that require external scrambling and al-
lows implementation with no external clock recovery or
clock generation functions required See Figure 3-21
PLAYER
The following figures illustrate how the PLAYER
can be connected to various types of PMDs
DP83257 PLAYER
or Shielded Twisted Pair (SDDI) PMD using the Primary
PMD Interface
PLAYER
Pair (UTP) PMD using the Alternate PMD Interface
a
a
device is connected to an Unshielded Twisted
TO PMD CONNECTIONS
a
device is connected to a Fiber Optic
TL F 11708 – 47
TL F 11708 – 48
a
device