VITESSE
SEMICONDUCTOR CORPORATION
Target Specification
VSC8115
Features
鈥?Performs clock and data recovery for
622.08Mb/s (STS-12/OC-12/STM-4) or
155.52Mb/s (STS-3/OC-3/STM-1) NRZ data
鈥?Meets Bellcore, ITU and ANSI Specifications
for Jitter Performance
鈥?19.44MHz reference frequency LVTTL Input
鈥?Lock Detect output pin monitors data run length
and frequency drift from the reference clock
鈥?Data is Retimed at the Output
鈥?Active High Signal Detect LVPECL Input
STS-12/STS-3 Multi Rate
Clock and Data Recovery Unit
鈥?Low-jitter high speed outputs can be configured
as either LVPECL or low power LVDS
鈥?Low power - 0.188 Watts Typical Power
鈥?+3.3V Power Supply
鈥?20 Pin TSSOP Package
鈥?Requires One External Capacitor
鈥?PLL bypass operation facilitates the board
debug process
General Description
The VSC8115 functions as a clock and data recovery unit for SONET/SDH-based equipment to derive high
speed timing signals. The VSC8115 recovers the clock from the scrambled NRZ data operating at 622.08Mb/s
(STS-12/OC-12/STM-4) or 155.52Mb/s (STS-3/OC-3/STM-1). After the clock is recovered, the data is retimed
using an output flip-flop. Both recovered clock and retimed data outputs can be configured as LVDS or
LVPECL signals to facilitate a low-jitter and low power interface.
VSC8115 Block Diagram
STS12
Divider
CAP+
CAP-
VCO
BYPASS
DATAIN+/-
SD
LOCKREFN
REFCLK
0
1
2
2
Phase/
Freq
Detector
Loop Filter
2
LOCKDET
DATAOUT+/-
CLKOUT+/-鹵
G52272-0, Rev. 1.1
9/29/00
漏
VITESSE
SEMICONDUCTOR CORPORATION
741 Calle Plano, Camarillo, CA 93012 鈥?805/388-3700 鈥?FAX: 805/987-5896
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