L-FW802B-DB LSI, L-FW802B-DB Datasheet - Page 12

• Manufacturer Part Number: L-FW802B-DB
• Manufacturer: LSI

Specifications of L-FW802B-DB

• Lead Free Status / RoHS Status: Compliant

FW802B Low-Power PHY IEEE 1394A-2000
Two-Cable Transceiver/Arbiter Device
Application Information
Crystal Selection Considerations
The FW802B is designed to use an external 24.576 MHz parallel resonant fundamental mode crystal connected
between the XI and XO terminals to provide the reference for an internal oscillator circuit. The IEEE 1394a-2000
standard requires that FW802B have less than ±100 ppm total variation from the nominal data rate, which is
directly influenced by the crystal. To achieve this, it is recommended that an oscillator with a nominal 50 ppm or
less frequency tolerance be used.
The total frequency variation must be kept below ±100 ppm from nominal with some allowance for error introduced
by board and device variations. Trade offs between frequency tolerance and stability may be made as long as the
total frequency variation is less than ±100 ppm.
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40
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37
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TPBIAS1
TPA1+
TPA1–
TPB1+
TPB1–
TPBIAS0
TPA0+
TPA0–
TPB0+
TPB0–
220 pF
56 Ω
56 Ω
56 Ω
5 kΩ
56 Ω
TPBIAS1
0.33 µF
(continued)
POWER
Figure 4. Typical Port Termination Network
CABLE
VP
5
3
1
USE SAME PORT TERMINATION NETWORK AS ILLUSTRATED BELOW.
6
4
2
VG
IEEE 1394-1995 STANDARD
CONNECTOR
Data Sheet, Rev. 3
Agere Systems Inc.
May 2004
5-6930 (F)