參數(shù)資料
型號(hào)： XRT91L30IQTR
廠商： Exar Corporation
文件頁(yè)數(shù)： 22/40頁(yè)
文件大?。?/td> 0K
描述： IC TXRX SONET/SDH 8BIT 64QFP
標(biāo)準(zhǔn)包裝： 1,000
類型： 收發(fā)器
規(guī)程： SONET/SDH
電源電壓： 3.3V
安裝類型： 表面貼裝
封裝/外殼： 64-FQFP
供應(yīng)商設(shè)備封裝： 64-PQFP（10x10）
包裝： 帶卷 (TR)
XRT91L30
25
REV. 1.0.2
STS-12/STM-4 OR STS-3/STM-1 SONET/SDH TRANSCEIVER
3.6
Clock Multiplier Unit (CMU) and Re-Timer
The clock synthesizer uses a 77.76 MHz or a 19.44 MHz reference clock to generate the 622.08 MHz (for STS-
12/STM-4) or 155.52 MHz (for STS-3/STM-1) SONET/SDH transmit serial data rate frequency. Differential
LVPECL input REFCLKP/N accepts a clock reference of 77.76 MHz or 19.44 MHz to synthesize a high speed
622.08 MHz clock for STS-12/STM-4 or 155.52 MHz clock for STS-3/STM-1 applications. Optionally, if a
Differential LVPECL clock source is not available, TTLREFCLK can accept an LVTTL clock signal. The clock
synthesizer uses a PLL to lock-on to the differential input REFCLKP/N or Single-Ended input TTLREFCLK
reference clock. The REFCLKP/N input should be generated from an LVPECL crystal oscillator which has a
frequency accuracy better than 20ppm in order for the transmitted data rate frequency to have the necessary
accuracy required for SONET systems. If the TTLREFCLK
reference clock is used, the TTLREFCLK
reference input should be tied to a LVTTL crystal oscillator with 20ppm accuracy. The two reference clocks are
XNOR’ed and the choice between the LVPECL and LVTTL clocks are controlled tying either REFCLKP or
TTLREFCLK to ground. Table 1 shows the CMU reference clock frequency settings. Table 15 specifies the
Clock Multiplier Unit’s requirements for the Reference clock.
TABLE 15: CLOCK MULTIPLIER UNIT’S REQUIREMENTS FOR
REFCLK
Jitter specification is defined using a 12kHz to 1.3/5MHz LP-HP single-pole filter.
1These reference clock jitter limits are required for the outputs to meet SONET system level jitter requirements (<10 mUI
rms).
2Required to meet SONET output frequency stability requirements.
3.7
Loop Timing and Clock Control
Two types of loop timing are possible in the XRT91L30.
In the internal loop timing mode, loop timing is controlled by the LOOPTIME pin. This mode is selected by
asserting the LOOPTIME signal to a high level. When the loop timing mode is activated, the CMU synthesized
hi-speed reference clock input to the Retimer is replaced with the hi-speed internally recovered receive clock
coming from the CDR. Under this condition both the transmit and receive sections are synchronized to the
internally recovered receive clock. Loop time mode directly locks the Retimer to the recovered receive clock.
In external loop timing mode, the XRT91L30 allows the user the flexibility of using an externally recovered
receive clock for retiming the high speed serial data. First, the CDRDIS input pin should be set high. By doing
so, the internal CDR is disabled and bypassed and the XRT91L30 will sample the incoming high speed serial
data on RXIP/N with the externally recovered receive clock connected to the XRXCLKIP/N inputs. In this state,
the receive clock de-jittering and recovery is done externally and fed thru XRXCLKIP/N and the XRT91L30 will
sample RXIP/N on the rising edge of XRXCLKIP/N. Secondly, the LOOPTIME pin must also be set high in
order to select the externally recovered receive clock on XRXCLKIP/N as the reference clock source for the
transmit serial data output stream TXOP/N.
NAME
PARAMETER
MIN
TYP
MAX
UNITS
REFDUTY
Reference clock duty cycle
40
60
%
REFJIT
Reference clock jitter (rms) with 19.44 MHz reference1
5
ps
REFJIT
Reference clock jitter (rms) with 77.76 MHz reference1
13
ps
REFTOL
Reference clock frequency tolerance2
-20
+20
ppm
相關(guān)PDF資料
PDF描述
VI-2NH-IW-F2 CONVERTER MOD DC/DC 52V 100W
VI-2NF-IX-B1 CONVERTER MOD DC/DC 72V 75W
MS27497T14F35P CONN RCPT 37POS WALL MNT W/PINS
MS27473E22F21PA CONN PLUG 21POS STRAIGHT W/PINS
MS27497T14B35P CONN RCPT 37POS WALL MNT W/PINS
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
XRT91L30IQTR-F 功能描述:網(wǎng)絡(luò)控制器與處理器 IC 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
XRT91L31 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
XRT91L31_08 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
XRT91L31ES 功能描述:總線收發(fā)器 RoHS:否 制造商:Fairchild Semiconductor 邏輯類型:CMOS 邏輯系列:74VCX 每芯片的通道數(shù)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(shí)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
XRT91L31IQ 功能描述:網(wǎng)絡(luò)控制器與處理器 IC SONET/SDH, FULL DPLX 3.3V I/O, LOS, CMU 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
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*