參數(shù)資料
型號(hào): XRT75R03D
廠商: Exar Corporation
英文描述: THREE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCRONIZER
中文描述: Three頻道E3/DS3/STS-1線路接口單元與SONET DESYNCRONIZER
文件頁數(shù): 110/134頁
文件大小: 803K
代理商: XRT75R03D
XRT75R03D
REV. 1.0.2
THREE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCRONIZER
105
span thousands of miles, traverse many different pieces of equipments, and even cross International
boundaries; in practice, the SONET/SDH network is NOT synchronized to a single clock source.
In practice, the SONET/SDH network can be thought of as being divided into numerous "Synchronization
Islands". Each of these "Synchronization Islands" will consist of numerous pieces of SONET Terminal
Equipment. Each of these pieces of SONET Terminal Equipment will all be synchronized to a single Stratum-1
clock source which is the most accurate clock source within the Synchronization Island. Typically a
"Synchronization Island" will consist of a single "Timing Master" equipment along with multiple "Timing Slave"
pieces of equipment. This "Timing Master" equipment will be directly connected to the Stratum-1 clock source
and will have the responsibility of distributing a very accurate clock signal (that has been derived from the
Stratum 1 clock source) to each of the "Timing Slave" pieces of equipment within the "Synchronization Island".
The purpose of this is to permit each of the "Timing Slave" pieces of equipment to be "synchronized" with the
"Timing Master" equipment, as well as the Stratum 1 Clock source. Typically this "clock distribution" is
performed in the form of a BITS (Building Integrated Timing Supply) clock, in which a very precise clock signal
is provided to the other pieces of equipment via a T1 or E1 line signal.
Many of these "Synchronization Islands" will use a Stratum-1" clock source that is derived from GPS pulses
that are received from Satellites that operate at Geo-synchronous orbit. Other "Synchronization Islands" will
use a Stratum-1" clock source that is derived from a very precise local atomic clock. As a consequence,
different "Synchronization Islands" will use different Stratum 1 clock sources. The up-shot of having these
"Synchronization Islands" that use different "Stratum-1 clock" sources, is that the Stratum 1 Clock frequencies,
between these "Synchronization Islands" are likely to be slightly different from each other. These "frequency-
differences" within Stratum 1 clock sources will result in "clock-domain changes" as a SONET signal (that is
traversing the SONET network) passes from one "Synchronization Island" to another.
The following section will describe how these "frequency differences" will cause a phenomenon called "pointer
adjustments" to occur in the SONET Network.
10.3.3
Causes of Pointer Adjustments
The best way to discuss how pointer adjustment events occur is to consider an STS-1 signal, which is driven by
a timing reference of frequency f1; and that this STS-1 signal is being routed to a network equipment (that
resides within a different "Synchronization Island") and processes STS-1 data at a frequency of f2.
N
OTE
:
Clearly, both frequencies f1 and f2 are at the STS-1 rate (e.g., 51.84MHz). However, these two frequencies are
likely to be slightly different from each other.
Now, since the STS-1 signal (which is of frequency f1) is being routed to the network element (which is
operating at frequency f2), the typical design approach for handling "clock-domain" differences is to route this
STS-1 signal through a "Slip Buffer" as illustrated below.
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XRT75R03DIV THREE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCRONIZER
XRT75R03 THREE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
XRT75R03IV THREE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
XRT75R03D_06 制造商:EXAR 制造商全稱:EXAR 功能描述:EXAR DATA SHEET FORMAT TEMPLATES
XRT75R03DES 功能描述:時(shí)鐘合成器/抖動(dòng)清除器 3CH T3/E3/STS1LIU+D 3.3V W/REDUNDANCY RoHS:否 制造商:Skyworks Solutions, Inc. 輸出端數(shù)量: 輸出電平: 最大輸出頻率: 輸入電平: 最大輸入頻率:6.1 GHz 電源電壓-最大:3.3 V 電源電壓-最小:2.7 V 封裝 / 箱體:TSSOP-28 封裝:Reel
XRT75R03DIV 功能描述:時(shí)鐘合成器/抖動(dòng)清除器 3CHNNEL E3/DS3/STS 1 JITTER ATTENUATOR RoHS:否 制造商:Skyworks Solutions, Inc. 輸出端數(shù)量: 輸出電平: 最大輸出頻率: 輸入電平: 最大輸入頻率:6.1 GHz 電源電壓-最大:3.3 V 電源電壓-最小:2.7 V 封裝 / 箱體:TSSOP-28 封裝:Reel
XRT75R03DIV-F 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 3-Ch E3/DS3/STS-1 RoHS:否 制造商:Micrel 產(chǎn)品:Controller Area Network (CAN) 收發(fā)器數(shù)量: 數(shù)據(jù)速率: 電源電流(最大值):595 mA 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PBGA-400 封裝:Tray
XRT75R03DIVTR 功能描述:時(shí)鐘合成器/抖動(dòng)清除器 3CHNNEL E3/DS3/STS 1 JITTER ATTENUATOR RoHS:否 制造商:Skyworks Solutions, Inc. 輸出端數(shù)量: 輸出電平: 最大輸出頻率: 輸入電平: 最大輸入頻率:6.1 GHz 電源電壓-最大:3.3 V 電源電壓-最小:2.7 V 封裝 / 箱體:TSSOP-28 封裝:Reel