參數(shù)資料
型號: IDT82V2108PX
廠商: IDT, Integrated Device Technology Inc
文件頁數(shù): 287/292頁
文件大?。?/td> 0K
描述: IC FRAMER T1/J1/E1 8CH 128-PQFP
標(biāo)準(zhǔn)包裝: 11
控制器類型: T1/E1/J1 調(diào)幀器
接口: 并聯(lián)
電源電壓: 2.97 V ~ 3.63 V
電流 - 電源: 160mA
工作溫度: -40°C ~ 85°C
安裝類型: 表面貼裝
封裝/外殼: 128-BFQFP
供應(yīng)商設(shè)備封裝: 128-PQFP(14x20)
包裝: 托盤
其它名稱: 82V2108PX
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁第97頁第98頁第99頁第100頁第101頁第102頁第103頁第104頁第105頁第106頁第107頁第108頁第109頁第110頁第111頁第112頁第113頁第114頁第115頁第116頁第117頁第118頁第119頁第120頁第121頁第122頁第123頁第124頁第125頁第126頁第127頁第128頁第129頁第130頁第131頁第132頁第133頁第134頁第135頁第136頁第137頁第138頁第139頁第140頁第141頁第142頁第143頁第144頁第145頁第146頁第147頁第148頁第149頁第150頁第151頁第152頁第153頁第154頁第155頁第156頁第157頁第158頁第159頁第160頁第161頁第162頁第163頁第164頁第165頁第166頁第167頁第168頁第169頁第170頁第171頁第172頁第173頁第174頁第175頁第176頁第177頁第178頁第179頁第180頁第181頁第182頁第183頁第184頁第185頁第186頁第187頁第188頁第189頁第190頁第191頁第192頁第193頁第194頁第195頁第196頁第197頁第198頁第199頁第200頁第201頁第202頁第203頁第204頁第205頁第206頁第207頁第208頁第209頁第210頁第211頁第212頁第213頁第214頁第215頁第216頁第217頁第218頁第219頁第220頁第221頁第222頁第223頁第224頁第225頁第226頁第227頁第228頁第229頁第230頁第231頁第232頁第233頁第234頁第235頁第236頁第237頁第238頁第239頁第240頁第241頁第242頁第243頁第244頁第245頁第246頁第247頁第248頁第249頁第250頁第251頁第252頁第253頁第254頁第255頁第256頁第257頁第258頁第259頁第260頁第261頁第262頁第263頁第264頁第265頁第266頁第267頁第268頁第269頁第270頁第271頁第272頁第273頁第274頁第275頁第276頁第277頁第278頁第279頁第280頁第281頁第282頁第283頁第284頁第285頁第286頁當(dāng)前第287頁第288頁第289頁第290頁第291頁第292頁
IDT82V2108
T1 / E1 / J1 OCTAL FRAMER
Functional Description
84
March 5, 2009
3.19
JITTER ATTENUATOR (RJAT/TJAT)
The Jitter Attenuator of each framer operates independently
3.19.1
E1 MODE
Two Jitter Attenuators are provided independently in the receive
path and the transmit path.
The Jitter Attenuator integrates a FIFO and a DPLL. The smoothed
clock output from the jitter attenuator is generated by adaptively dividing
the 49.152MHz XCK according to the phase difference between the out-
put smoothed clock and the input reference clock. The ratio between the
frequency of the input reference clock and the frequency applied to the
phase discriminator input is equal to the (N1 + 1) (the N1 is in b7~0, E1-
021H for receive path and in b7~0, E1-025H for transmit path). The ratio
between the frequency of the output smoothed clock and the frequency
applied to the phase discriminator input is equal to the (N2 + 1) (the N2
is in b7~0, E1-022H for receive path and in b7~0, E1-026H for transmit
path). The phase fluctuations of the input reference clock are attenuated
by dividing the input reference clock and output smoothed clock by the
(N1 + 1) and the (N2 + 1) respectively in the DPLL so that the frequency
of the output smoothed clock is equal to the average frequency of the
input reference clock. The phase fluctuations with a jitter frequency
above 8.8 Hz are attenuated by 6 dB per octave when the N1 (b7~0, E1-
021H for receive path and b7~0, E1-025H for transmit path) and the N2
(b7~0, E1-022H for receive path and b7~0, E1-026H for transmit path)
are set to their default value. It will change when the N1 and the N2 are
changed. Generally, when the N1 and the N2 increase, the curves of the
Jitter Tolerance and Jitter Transfer in the graph will left-shift and when
N1 and N2 decrease, they will right-shift. The phase fluctuations (wan-
der) with frequency below 8.8 Hz are tracked by the output smoothed
clock. The output smoothed clock is used to clock the data out of the
FIFO.
The FIFO is 48 bits deep. If data is still written into the FIFO when
the FIFO is already full, overflow will occur and the OVRI (b1, E1-020H
for receive path and b1, E1-024H for transmit path) will indicate. If data
is still read from the FIFO when the FIFO is already empty, under-run will
occur and the UNDI (b0, E1-020H for receive path and b0, E1-024H for
transmit path) will indicate. Thus, if the OVRE (b2, E1-023H for receive
path and b2, E1-027H for transmit path) and the UNDE (b3, E1-023H for
receive path and b3, E1-027H for transmit path) are set respectively, the
interrupts on the INT pin will occur. The jitter attenuation can be limited
by setting the LIMIT (b0, E1-023H for receive path and b0, E1-027H for
transmit path) to keep the FIFO 1 UI away from being full or empty.
Thus, the DPLL will track the jitter of the input reference clock by
increasing or decreasing the frequency of the output smoothed clock to
prevent the FIFO being empty or full. The FIFO can also self-center its
read pointer by setting the CENT (b4, E1-023H for receive path and b4,
E1-027H for transmit path). The FIFO can be set to be bypassed by the
FIFOBYP (b7, E1-000H for receive path and b7, E1-002H for transmit
path).
However, in the Transmit Clock Master mode, the TJAT should be
bypassed.
3.19.1.1
Jitter Characteristics
Each Jitter Attenuator block provides excellent jitter tolerance and
jitter attenuation while generating minimal residual jitter. It can accom-
modate up to 43 UIpp of input jitter at jitter frequencies above 9 Hz. For
jitter frequencies below 9 Hz, which can be correctly called wander, the
tolerance increases 20 dB per decade. In most applications the each Jit-
ter Attenuator block will limit jitter tolerance at lower jitter frequencies
only. For high frequency jitter, above 10 kHz for example, other factors
such as clock and data recovery circuitry may limit jitter tolerance and
must be considered. For low frequency wander, below 10 Hz for exam-
ple, other factors such as slip buffer hysteresis may limit wander toler-
ance and must be considered. The Jitter Attenuator blocks meet the low
frequency jitter tolerance requirements ITU-T Recommendation G.823.
The Jitter Attenuator exhibits negligible jitter gain for jitter frequen-
cies below 9 Hz, and attenuates jitter at frequencies above 9 Hz by 20
dB per decade. In most applications the Jitter Attenuator blocks will
determine jitter attenuation for higher jitter frequencies only. Wander,
below 10 Hz for example, will essentially be passed unattenuated
through the Jitter Attenuator. Jitter, above 10 Hz for example, will be
attenuated as specified, however, outgoing jitter may be dominated by
the generated residual jitter in cases where incoming jitter is insignifi-
cant. This generated residual jitter is directly related to the use of 24X
(49.152 MHz) digital phase locked loop for transmit clock generation.
The Jitter Attenuator meets the jitter transfer requirements of ITU-T
Recommendations G.737, G.738, G.739, and G.742.
3.19.1.2
Jitter Tolerance
Jitter tolerance is the maximum input phase jitter at a given jitter
frequency that a device can accept without exceeding its linear operat-
ing range, or corrupting data. For the Jitter Attenuator, the input jitter tol-
erance is 43 UIpp with no frequency offset. The frequency offset is the
difference between the frequency of XCK divided by 24 and that of the
input reference clock.
Refer to Figure 65 for the Jitter Tolerance.
3.19.1.3
Jitter Transfer
The output jitter for jitter frequencies from 0 to 9 Hz is no more than
0.1 dB greater than the input jitter. Jitter frequencies above 9 Hz are
attenuated at a level of 6 dB per octave, as shown in Figure 66.
3.19.1.4
Frequency Range
In the non-attenuating mode, that is, when the FIFO is within 1 UI of
overrunning or under running, the tracking range is 1.963 to 2.133 MHz.
The guaranteed linear operating range is 2.048 MHz ± 1278 Hz with no
jitter or XCK frequency offset.
相關(guān)PDF資料
PDF描述
VE-2TP-IX-S CONVERTER MOD DC/DC 13.8V 75W
VE-2TN-IX-S CONVERTER MOD DC/DC 18.5V 75W
PIC16LF1904-E/P MCU 7KB FLASH 256B RAM 40PDIP
IDT82V2108PXG8 IC FRAMER T1/J1/E1 8CH 128-PQFP
IDT82V2108PX8 IC FRAMER T1/J1/E1 8CH 128-PQFP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
IDT82V2108PX8 功能描述:IC FRAMER T1/J1/E1 8CH 128-PQFP RoHS:否 類別:集成電路 (IC) >> 接口 - 控制器 系列:- 標(biāo)準(zhǔn)包裝:4,900 系列:- 控制器類型:USB 2.0 控制器 接口:串行 電源電壓:3 V ~ 3.6 V 電流 - 電源:135mA 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:36-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:36-QFN(6x6) 包裝:* 其它名稱:Q6396337A
IDT82V2108PXG 功能描述:IC FRAMER T1/J1/E1 8CH 128-PQFP RoHS:是 類別:集成電路 (IC) >> 接口 - 控制器 系列:- 標(biāo)準(zhǔn)包裝:4,900 系列:- 控制器類型:USB 2.0 控制器 接口:串行 電源電壓:3 V ~ 3.6 V 電流 - 電源:135mA 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:36-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:36-QFN(6x6) 包裝:* 其它名稱:Q6396337A
IDT82V2108PXG8 功能描述:IC FRAMER T1/J1/E1 8CH 128-PQFP RoHS:是 類別:集成電路 (IC) >> 接口 - 控制器 系列:- 標(biāo)準(zhǔn)包裝:4,900 系列:- 控制器類型:USB 2.0 控制器 接口:串行 電源電壓:3 V ~ 3.6 V 電流 - 電源:135mA 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:36-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:36-QFN(6x6) 包裝:* 其它名稱:Q6396337A
IDT82V2604 制造商:IDT 制造商全稱:Integrated Device Technology 功能描述:INVERSE MULTIPLEXING FOR ATM IDT82V2604
IDT82V2604BB 功能描述:IC INVERSE MUX 4CH ATM 208-BGA RoHS:否 類別:集成電路 (IC) >> 接口 - 專用 系列:- 標(biāo)準(zhǔn)包裝:3,000 系列:- 應(yīng)用:PDA,便攜式音頻/視頻,智能電話 接口:I²C,2 線串口 電源電壓:1.65 V ~ 3.6 V 封裝/外殼:24-WQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:24-QFN 裸露焊盤(4x4) 包裝:帶卷 (TR) 安裝類型:表面貼裝 產(chǎn)品目錄頁面:1015 (CN2011-ZH PDF) 其它名稱:296-25223-2