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參數(shù)資料
| 型號： | XRT5894 |
| 廠商： | Exar Corporation |
| 英文描述： | Four-Channel E1 Line Interface (3.3V or 5.0V)(四通道E1 3.3V線接口單元) |
| 中文描述： | 四通道E1線路接口（3.3V或5.0V），（四通道素E1 3.3線接口單元） |
| 文件頁數(shù)： | 11/19頁 |
| 文件大小： | 867K |
| 代理商： | XRT5894 |
XRT5894
11
Rev. 1.10
SYSTEM DESCRIPTION
This device is a fourchannelE1 transceiverthatprovides
an electrical interface for 2.048Mbps applications. Its
unique architecture includes four receiver circuits that
convert ITU G.703 compliant bipolar signals to TTL
compatible logic levels. Each receiver includes a LOS
(Loss of Signal) detection circuit that may be configured
for eithera fixed ora user-programmable LOS response
time delay.
Similarly, in the transmit direction, four
transmitters convertTTL compatible logic levels toG.703
compatible bipolar signals.
operatedeitherwithRZ, orNRZ datatypes. InNRZ mode
a transmit clock is required as well.
description applies to any of the four receivers or
transmitters contained in the XRT5894. Therefore, the
suffix numbers for a particular channel are deleted for
simplicity. i.e. “RTIP” applies to RTIP1 through RTIP4.
Each transmitter may be
The following
Receiver Operation
A bipolar signal is transformer-coupled to the receiver
differentialinputs (RTIP andRRING). Thereceiveris able
totolerate upto12dB ofline loss measuredat1.024MHz.
Itcontains slicing circuitry thatautomatically samples the
incoming data ata fixedpercentage (50% nominal) ofthe
peak signal amplitude. A precision peak detector
maintains the slicing levelaccuracy. The TTL compatible
receiver output data rails appear at the RXPOS and
RXNEG pins. The pulse widthofthis data; whichis inRZ
format, is a function of the amount of the cable loss
present.
Receiver Loss Of Signal Detection (LOS)
Absence ofsignalatany receiverinputis detectedby the
loss ofsignal(LOS) circuit. OneLOS detectioncircuitryis
provisionedforeachreceiver. The LOS signalis asserted
(LOS=1) whena LOS conditionis detectedandis cleared
(LOS=0) when a valid input signal is restored.
Two modes of LOS circuit operation are supported.
These distinct modes are called “automatic” and
“user-programmable”. When LOSSEL (pin 25) is set to
logic “1”, theautomatic modeis selected. Inthis modethe
LOS condition will be declared and cleared in full
compliancewithITU G.775specification. WhenLOSSEL
is connected to logic “0”, the user-programmable delay
mode is enabled. In this mode the userhas the optionof
extending the delay of LOS declaration and clearing
specified in the ITU G.775. This is done by providing a
user-supplied clock to LOSCNT (pin 45).
programmable mode” is provisioned to allow systems
designers to comply with older versions of LOS
specifications inlegacy systems. Itneeds to be stressed
that the delay for declaration and clearing of the LOS
conditionwillneverbe less thanthe rangespecifiedinthe
G.775 specification (10-255 pulse intervals).
The “user
The LOS detection/clearing circuitry of the XRT5894 in
“automatic” mode will detect LOS when the incoming
signalhas “notransitions”i.e. whenthesignallevelis less
thanorequaltoa signallevelA
D
dB belownominalsignal
level,forNconsecutivepulseintervals,where10<N<255.
The value of A
D
can vary between 10dB to 32dB
depending on the ones density of the incoming signal
assuming the received data has minimum permissible
ones density. Furthermore LOS detect is cleared when
the incoming signalhas “transitions,” i.e. whenthe signal
level is greater than or equal to a signal level of A
C
dB
below nominal, for N consecutive pulse intervals, where
10<N<255. The value of A
C
can vary between 9dB to
31dB depending on the ones density of the incoming
signal assuming the received data has minimum
permissible ones density. Eachpulse intervalis 488ns at
E1rates. The absolute value ofA
C
is always smallerthan
A
D
by at least 1dB.
The LOS detection/clearing criteria described above is
fully compliantwithG.775 LOS specification. Inthe “user
programmable” mode the user has the option of
extending the declarationandclearing delay (10<N<255)
by an amount which is equal to 2048 x T. T is the time
period of the clock supplied to LOSCNT (pin 45) by the
user.
Nominal signal level is defined as 2.37V peak measured
between RTIP or RRING and ground. (This voltage will
be presentin 75
applications using a 1:2 CT ratio input
transformer terminated in 300
with the center tap
grounded with 0dB of cable and a 2.37V peak amplitude
transmit pulse at the cable input.)
Transmitters
This device contains four identical ITU G.703 compliant
transmitters. The output stage of each transmitter is a
differential voltage driver. External resistors need to be
connected to the primary of output transformer. This is
necessary to maintain an accurate source impedance
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| XRT5894ES | 功能描述:外圍驅(qū)動器與原件 - PCI 4 CH E1 AFE RoHS:否 制造商:PLX Technology 工作電源電壓: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:FCBGA-1156 封裝:Tray |
| XRT5894IV | 制造商:EXAR 制造商全稱:EXAR 功能描述:Four-Channel E1 Line Interface (3.3V or 5.0V) |
| XRT5894IV-F | 功能描述:外圍驅(qū)動器與原件 - PCI 3.3V or 5V 4-ch E1 temp -45 to 85C RoHS:否 制造商:PLX Technology 工作電源電壓: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:FCBGA-1156 封裝:Tray |
| XRT5894IVTR-F | 功能描述:接口 - 專用 QuadE1 LIU3.3/5.5V RoHS:否 制造商:Texas Instruments 產(chǎn)品類型:1080p60 Image Sensor Receiver 工作電源電壓:1.8 V 電源電流:89 mA 最大功率耗散: 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:BGA-59 |
| XRT5897 | 制造商:EXAR 制造商全稱:EXAR 功能描述:Seven-Channel E1 Line Interface |
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