參數資料
型號: XRT91L31IQ
廠商: EXAR CORP
元件分類: 數字傳輸電路
英文描述: STS-12/STM-4 OR STS-3/STM-1 SONET/SDH TRANSCEIVER
中文描述: TRANSCEIVER, PQFP64
封裝: 10 X 10 MM, 2 MM HEIGHT, PLASTIC, QFP-64
文件頁數: 17/41頁
文件大?。?/td> 356K
代理商: XRT91L31IQ
xr
REV. 1.0.2
XRT91L31
STS-12/STM-4 OR STS-3/STM-1 SONET/SDH TRANSCEIVER
15
2.3
The clock and data recovery (CDR) unit accepts the high speed NRZ serial data from the Differential LVPECL
receiver and generates a clock that is the same frequency as the incoming data. The clock recovery can either
utilize the transmitter’s CMU reference clock from either REFCLKP/N or TTLREFCLK or it can use
independent clock source CDRAUXREFCLK to train and monitor its clock recovery PLL. Initially upon startup,
the PLL locks to the local reference clock within ±500 ppm. Once this is achieved, the PLL then attempts to
lock onto the incoming receive data stream. Whenever the recovered clock frequency deviates from the local
reference clock frequency by more than approximately ±500 ppm, the clock recovery PLL will switch and lock
back onto the local reference clock. Whenever a Loss of Lock or a Loss of Signal event occurs, the CDR will
continue to supply a receive clock (based on the local reference) to the framer/mapper device. When the
LOSEXT is asserted by the optical module or when LOS is detected, the receive parallel data output will be
forced to a logic zero state for the entire duration that a LOS condition is detected. This acts as a receive data
mute upon LOS function to prevent random noise from being misinterpreted as valid incoming data. When the
LOSEXT becomes inactive and the recovered clock is determined to be within ±500 ppm accuracy with respect
to the local reference source and LOS is no longer declared, the clock recovery PLL will switch and lock back
onto the incoming receive data stream. Table 5 shows Clock and Data Recovery reference clock settings.
Table 6 specifies the Clock and Data Recovery Unit performance characteristics.
T
ABLE
5: C
LOCK
D
ATA
R
ECOVERY
UNIT
REFERENCE
CLOCK
SETTINGS
Receive Clock and Data Recovery
1
Requires frequency accuracy better than 20ppm in order for the transmitted data rate frequency to have the necessary
accuracy required for SONET systems.
2
CDRAUXREFCLK requires accuracy of 77.76 MHz +/- 500ppm.
CMUFREQSEL CDRREFSEL
STS12/
STS3
REFCLKP/N
1OR
TTLREFCLK
1
F
REQUENCY
(MH
Z
)
CDRAUXREFCLK
2
F
REQUENCY
(MH
Z
)
CDR O
UTPUT
F
REQUENCY
(MH
Z
)
0
0
0
77.76 MHz
not used
155.52
0
0
1
77.76 MHz
not used
622.08
1
0
0
19.44 MHz
not used
155.52
1
0
1
19.44 MHz
not used
622.08
X
1
0
not referenced by CDR
77.76 MHz
155.52
X
1
1
not referenced by CDR
77.76 MHz
622.08
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相關代理商/技術參數
參數描述
XRT91L31IQ-F 功能描述:網絡控制器與處理器 IC 8-Bit TTL 3.3V temp -45 to 85C;UART RoHS:否 制造商:Micrel 產品:Controller Area Network (CAN) 收發(fā)器數量: 數據速率: 電源電流(最大值):595 mA 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:PBGA-400 封裝:Tray
XRT91L31IQ-F 制造商:Exar Corporation 功能描述:SONET Transceiver IC
XRT91L31IQTR 功能描述:總線收發(fā)器 SONET/SDH, FULL DPLX 3.3V I/O, LOS, CMU RoHS:否 制造商:Fairchild Semiconductor 邏輯類型:CMOS 邏輯系列:74VCX 每芯片的通道數量:16 輸入電平:CMOS 輸出電平:CMOS 輸出類型:3-State 高電平輸出電流:- 24 mA 低電平輸出電流:24 mA 傳播延遲時間:6.2 ns 電源電壓-最大:2.7 V, 3.6 V 電源電壓-最小:1.65 V, 2.3 V 最大工作溫度:+ 85 C 封裝 / 箱體:TSSOP-48 封裝:Reel
XRT91L31IQTR-F 功能描述:總線收發(fā)器 SONET/SDH, FULL DPLX 3.3V I/O, LOS, CMU RoHS:否 制造商:Fairchild Semiconductor 邏輯類型:CMOS 邏輯系列:74VCX 每芯片的通道數量:16 輸入電平:CMOS 輸出電平:CMOS 輸出類型:3-State 高電平輸出電流:- 24 mA 低電平輸出電流:24 mA 傳播延遲時間:6.2 ns 電源電壓-最大:2.7 V, 3.6 V 電源電壓-最小:1.65 V, 2.3 V 最大工作溫度:+ 85 C 封裝 / 箱體:TSSOP-48 封裝:Reel
XRT91L32 制造商:EXAR 制造商全稱:EXAR 功能描述:STS-12/STM-4 OR STS-3/STM-1 SONET/SDH TRANSCEIVER