參數(shù)資料
型號(hào): MPC9608FAR2
廠商: INTEGRATED DEVICE TECHNOLOGY INC
元件分類(lèi): 時(shí)鐘及定時(shí)
英文描述: 9608 SERIES, PLL BASED CLOCK DRIVER, 10 TRUE OUTPUT(S), 0 INVERTED OUTPUT(S), PQFP32
封裝: 7 X 7 MM, LQFP-32
文件頁(yè)數(shù): 10/12頁(yè)
文件大小: 239K
代理商: MPC9608FAR2
MPC9608
TIMING SOLUTIONS
7
Due to the statistical nature of I/O jitter, an RMS value (1
σ)
is specified. I/O jitter numbers for other confidence factors (CF)
can be derived from Table 8.
The feedback trace delay is determined by the board layout
and can be used to fine-tune the effective delay through each
device. In the following example calculation a I/O jitter confi-
dence factor of 99.7% (
± 3σ) is assumed, resulting in a worst
case timing uncertainty from input to any output of -295 ps to
295 ps1 relative to CCLK:
tSK(PP) =
[-100 ps...100 ps] + [-150 ps...150 ps] +
[(15 ps . -3)...(15 ps . 3)] + tPD, LINE(FB)
tSK(PP) =
[-295 ps...295 ps] + tPD, LINE(FB)
Driving Transmission Lines
The MPC9608 clock driver was designed to drive high
speed signals in a terminated transmission line environment. To
provide the optimum flexibility to the user the output drivers
were designed to exhibit the lowest impedance possible. With
an output impedance of less than 20
the drivers can drive ei-
ther parallel or series terminated transmission lines. For more
information on transmission lines the reader is referred to Mo-
torola application note AN1091. In most high performance clock
networks point-to-point distribution of signals is the method of
choice. In a point-to-point scheme either series terminated or
parallel terminated transmission lines can be used. The parallel
technique terminates the signal at the end of the line with a 50
resistance to VCC ÷ 2.
This technique draws a fairly high level of DC current and
thus only a single terminated line can be driven by each output
of the MPC9608 clock driver. For the series terminated case
however there is no DC current draw, thus the outputs can drive
multiple series terminated lines. Figure 5 “Single versus Dual
Transmission Lines” illustrates an output driving a single series
terminated line versus two series terminated lines in parallel.
When taken to its extreme, the fanout of the MPC9608 clock
driver is effectively doubled due to its capability to drive multiple
lines.
The waveform plots in Figure 6 “Single versus Dual Line
Termination Waveforms” show the simulation results of an out-
put driving a single line versus two lines. In both cases the drive
capability of the MPC9608 output buffer is more than sufficient
to drive 50
transmission lines on the incident edge. From the
delay measurements in the simulations a delta of only 43 ps ex-
ists between the two differently loaded outputs. This suggests
that the dual line driving need not be used exclusively to main-
tain the tight output-to-output skew of the MPC9608. The output
waveform in Figure 6 “Single versus Dual Line Termination
Waveforms” shows a step in the waveform. This step is caused
by the impedance mismatch seen looking into the driver. The
parallel combination of the 36
series resistor plus the output
impedance does not match the parallel combination of the line
impedances. The voltage wave launched down the two lines will
equal:
VL =VS ( Z0 ÷ (RS +R0 +Z0))
Z0 = 50 || 50
RS =36 || 36
R0 =14
VL = 3.0 ( 25 ÷ (18 + 17 + 25))
=1.31 V
At the load end the voltage will double to 2.6 V due to the
near unity reflection coefficient. It will then increment towards
the quiescent 3.0 V in steps separated by one round trip delay
(in this case 4.0 ns).
TABLE 8. Confidence Facter CF
CF
Probability of clock edge within the distribution
± 1σ
0.68268948
± 2σ
0.95449988
± 3σ
0.99730007
± 4σ
0.99993663
± 5σ
0.99999943
± 6σ
0.99999999
1. Skew data are designed targets and pending device specifcations.
Figure 5. Single versus Dual Transmission Lines
14
IN
MPC9608
OUTPUT
BUFFER
RS = 36 ZO = 50
OutA
14
IN
MPC9608
OUTPUT
BUFFER
RS = 36 ZO = 50
OutB0
RS = 36 ZO = 50
OutB1
相關(guān)PDF資料
PDF描述
MPC9608AC PLL BASED CLOCK DRIVER, 10 TRUE OUTPUT(S), 0 INVERTED OUTPUT(S), PQFP32
MPC961CFAR2 961 SERIES, PLL BASED CLOCK DRIVER, 17 TRUE OUTPUT(S), 0 INVERTED OUTPUT(S), PQFP32
MPC961CFA 961 SERIES, PLL BASED CLOCK DRIVER, 17 TRUE OUTPUT(S), 0 INVERTED OUTPUT(S), PQFP32
MPC961CAC 961 SERIES, PLL BASED CLOCK DRIVER, 17 TRUE OUTPUT(S), 0 INVERTED OUTPUT(S), PQFP32
MPC961CFA MPC900 SERIES, PLL BASED CLOCK DRIVER, 17 TRUE OUTPUT(S), 0 INVERTED OUTPUT(S), PQFP32
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MPC961C 制造商:MOTOROLA 制造商全稱(chēng):Motorola, Inc 功能描述:LOW VOLTAGE ZERO DELAY BUFFER
MPC961CAC 功能描述:時(shí)鐘緩沖器 RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:5 最大輸入頻率:40 MHz 傳播延遲(最大值): 電源電壓-最大:3.45 V 電源電壓-最小:2.375 V 最大功率耗散: 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:LLP-24 封裝:Reel
MPC961CACR2 功能描述:IC BUFFER ZD 1:18 PLL 32-LQFP RoHS:是 類(lèi)別:集成電路 (IC) >> 時(shí)鐘/計(jì)時(shí) - 時(shí)鐘發(fā)生器,PLL,頻率合成器 系列:- 標(biāo)準(zhǔn)包裝:1,000 系列:- 類(lèi)型:時(shí)鐘/頻率合成器,扇出分配 PLL:- 輸入:- 輸出:- 電路數(shù):- 比率 - 輸入:輸出:- 差分 - 輸入:輸出:- 頻率 - 最大:- 除法器/乘法器:- 電源電壓:- 工作溫度:- 安裝類(lèi)型:表面貼裝 封裝/外殼:56-VFQFN 裸露焊盤(pán) 供應(yīng)商設(shè)備封裝:56-VFQFP-EP(8x8) 包裝:帶卷 (TR) 其它名稱(chēng):844S012AKI-01LFT
MPC961CFA 功能描述:IC ZDB CMOS LV 1:18 32-LQFP RoHS:否 類(lèi)別:集成電路 (IC) >> 時(shí)鐘/計(jì)時(shí) - 時(shí)鐘發(fā)生器,PLL,頻率合成器 系列:- 標(biāo)準(zhǔn)包裝:39 系列:- 類(lèi)型:* PLL:帶旁路 輸入:時(shí)鐘 輸出:時(shí)鐘 電路數(shù):1 比率 - 輸入:輸出:1:10 差分 - 輸入:輸出:是/是 頻率 - 最大:170MHz 除法器/乘法器:無(wú)/無(wú) 電源電壓:2.375 V ~ 3.465 V 工作溫度:0°C ~ 70°C 安裝類(lèi)型:* 封裝/外殼:* 供應(yīng)商設(shè)備封裝:* 包裝:*
MPC961PAC 功能描述:時(shí)鐘緩沖器 RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:5 最大輸入頻率:40 MHz 傳播延遲(最大值): 電源電壓-最大:3.45 V 電源電壓-最小:2.375 V 最大功率耗散: 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:LLP-24 封裝:Reel