參數(shù)資料
型號: PI90LVT211
廠商: Pericom Semiconductor Corp.
英文描述: 1:6 Differential Clock Distribution Chip
中文描述: 1:6差分時鐘分配芯片
文件頁數(shù): 7/9頁
文件大?。?/td> 185K
代理商: PI90LVT211
7
PS8535C 10/04/04
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PI90LV211/PI90LVT211
1:6 Differential Clock
Distribution Chip
General Desciption
The
PI90LV211 is a 1:6 fanout tree designed explicitly for low-skew,
high-speed clock distribution. The device was targeted to work in
conjunction with the PI90LV14 device to provide another level of
flexibility in the design and implementation of clock distribution
trees. The individual synchronous enable controls and multiplexed
clock inputs make the device ideal as the first level distribution unit
in a distribution tree. The device provides the ability to distribute
a lower speed scan or test clock along with the high-speed system
clock to ease the design of system diagnostics and self test
procedures. The individual enables could be used to allow for the
disabling of individual cards on a backplane in fault tolerant
designs.
Handling Open Inputs and Outputs
With the simultaneous switching characteristics and the tight skew
specifications of the P90LV211, the handling of the unused outputs
becomes critical. To minimize the noise generated on the die
all outputs should be terminated in pairs, i.e. both the true and
compliment outputs should be terminated even if only one of the
outputs will be used in the system. With both complimentary pairs
terminated, the current in the V
CC
pins will remain essentially
constant and thus inductance induced voltage glitches on V
CC
will
not occur. V
CC
glitches will result in distorted output waveforms
and degradations in the skew performance of the device.
The package parasitics of the 28-lead package cause the signals on
a given pin to be influenced by signals on adjacent pins. PI90LV211
is characterized and tested with all of the outputs switching,
therefore the numbers in the data book are guaranteed only for this
situation. If all of the outputs of the PI90LV211 are not needed and
there is a desire to save power, the unused output pairs can be left
unterminated. Unterminated outputs can influence the propagation
delay on adjacent pins by 15ps–20ps. Therefore, under these
conditions, this 15ps–20ps needs to be added to the overall skew
of the device. Pins which are separated by a package corner are not
considered adjacent pins in the context of propagation delay
influence. Therefore if all of the outputs on a single side of the
package are terminated, the specification limits in the data sheet will
apply.
Using the Enable Pins
Both the common enable (CEN) and the individual enables (ENx) are
synchronous to the CLK or SCLK input depending on which is
selected. The active low signals are clocked into the enable flip flops
on the negative edges of the PI90LV211 clock inputs. In this way,
the devices will only be disabled when the outputs are already in the
LOW state. The internal propagation delays are such that the delay
to the output through the distribution buffers is less than that
through the enable flip flops. This will ensure that the disabling of
the device will not slice any time off the clock pulse. On initial power
up, the enable flip flops will randomly attain a stable state; therefore
precautions should be taken on initial power up to ensure the
PI90LV211 is in the desired state.
Figure 8. Standard PI90LV211 LVDS Application
B
PI90LV14
PI90LV211
D0
D5
PI90LV14
相關(guān)PDF資料
PDF描述
PI90LVT211L STEEL COVER
PI90LVT211LE STEEL COVER
PI90LVT211Q 1:6 Differential Clock Distribution Chip
PI90LVT211QE 1:6 Differential Clock Distribution Chip
PI90LV211 1:6 Differential Clock Distribution Chip
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PI90LVT211L 制造商:PERICOM 制造商全稱:Pericom Semiconductor Corporation 功能描述:1:6 Differential Clock Distribution Chip
PI90LVT211LE 制造商:PERICOM 制造商全稱:Pericom Semiconductor Corporation 功能描述:1:6 Differential Clock Distribution Chip
PI90LVT211Q 制造商:PERICOM 制造商全稱:Pericom Semiconductor Corporation 功能描述:1:6 Differential Clock Distribution Chip
PI90LVT211QE 功能描述:時鐘驅(qū)動器及分配 1:6 LVDS Clock Distribution RoHS:否 制造商:Micrel 乘法/除法因子:1:4 輸出類型:Differential 最大輸出頻率:4.2 GHz 電源電壓-最大: 電源電壓-最小:5 V 最大工作溫度:+ 85 C 封裝 / 箱體:SOIC-8 封裝:Reel
PI90LVT211QEX 功能描述:時鐘驅(qū)動器及分配 1:6 LVDS Clock Distribution RoHS:否 制造商:Micrel 乘法/除法因子:1:4 輸出類型:Differential 最大輸出頻率:4.2 GHz 電源電壓-最大: 電源電壓-最小:5 V 最大工作溫度:+ 85 C 封裝 / 箱體:SOIC-8 封裝:Reel