VITESSE
SEMICONDUCTOR CORPORATION
Advance Product Information
VSC7146
Features
• Speed Selectable Full-Duplex Transceiver:
- 1.06/2.12Gb/s for FibreChannel
- 1.25/2.5Gb/s for Gigabit Ethernet
• 20-Bit TTL Interface for Transmit and
Receive Data at 125MHz
• Monolithic Clock Synthesis and Clock
Recovery - No External Components
• 125MHz TTL Reference Clock
2.5Gb/s, 20-Bit Transceiver
• Automatic Lock-to-Reference Function
• Suitable for Both Coaxial and Optical Link Appli-
cations
• Low Power Operation: 2.5 W max
• 80-Pin, 14mm Thermally-Enhanced EDQUAD
Package
• Single +3.3V Supply
General Description
The VSC7146 is a 2.5Gb/s Transceiver optimized for ease-of-use and efficiency in high-performance data
transmission systems. The VSC7146 accepts two 10-bit 8b/10b encoded transmit characters, latches them on
the rising edge of Transmit Byte Clock (TBC) and serializes the data onto the TX+/- differential outputs at a
baud rate, which is 20 times the TBC frequency. The VSC7146 also samples serial receive data on the RX+/-
differential inputs, recovers the clock and data, deserializes it onto two 10-bit receive characters, outputs a
recovered clocks at one-twentieth of the incoming baud rate and detects Fibre Channel “comma” characters.
The VSC7146 contains on-chip Phase-Lock Loop (PLL) circuitry for synthesis of the baud-rate transmit clock,
and extraction of the clock from the received serial stream. These circuits are fully monolithic and require no
external components.
Block Diagram
EWRAP
20
R0:19
QD
Serial to
Parallel
Retimed
Data
Recovered
Clock
QD
Clock
Recovery
2:1
RX+
RX-
RBC
RBCN
125 MHz
÷
20
Comma
Detect
RXRATE
COM_DET
EN_CDET
Frame
Logic
T0:19
TBC
20
DQ
Parallel
to Serial
2.5 Gb/s
Serial Data
2.5 Gb/s
DQ
TX+
TX-
125 MHz
REF
TXRATE
BCMN
PLL Clock
Multiply (x20)
2.5 GHz
Synthesized
Clock
G52162-0, Rev. 2.7
8/28/00
©
VITESSE
SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 • 805/388-3700 • FAX: 805/987-5896
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