參數(shù)資料
型號: AD8177ABPZ
廠商: Analog Devices Inc
文件頁數(shù): 31/40頁
文件大?。?/td> 0K
描述: IC VIDEO CROSSPOINT SWIT 676BGA
標準包裝: 1
功能: 視頻交叉點開關
電路: 3 x 16:5
電壓電源: 單/雙電源
電壓 - 電源,單路/雙路(±): 4.5 V ~ 5.5 V,±2.5V
電流 - 電源: 460mA
工作溫度: -40°C ~ 85°C
安裝類型: 表面貼裝
封裝/外殼: 676-BGA
供應商設備封裝: 676-BGA(27x27)
包裝: 管件
AD8177
Rev. 0 | Page 37 of 40
AD8177
OPn
ONn
IPn
INn
50
0
66
05
-02
6
One solution is to adjust the trace width to create a transmission
line of half the characteristic impedance and terminate the far
end with this resistance (25 Ω in a 50 Ω system). This is not
often practical as trace widths become large. In most cases, the
best practical solution is to place the half-characteristic impedance
resistor as close as possible (preferably less than 1.5 cm away)
and to reduce the parasitics of the stub (by removing the ground
plane under the stub, for example). In either case, the designer
must decide if the layout complexity created by a balanced,
terminated solution is preferable to simply grounding the undriven
input at the ball with no trace.
Figure 53. Fly-By Input Termination
(Grounds for the two transmission lines shown
must be tied together close to the INn pin.)
If multiple AD8177s are to be driven in parallel, a fly-by input
termination scheme is very useful, but the distance from each
AD8177 input to the driven input transmission line is a stub
that should be minimized in length and parasitics using the
discussed guidelines.
The examples discussed so far are for input termination, but the
theory is similar for output back-termination. Taking the AD8177
as an ideal voltage source, any distance of routing between the
AD8177 and a back-termination resistor is an impedance
mismatch that potentially creates reflections. For this reason,
back-termination resistors should also be placed close to the
AD8177. In practice, because back-termination resistors are
series elements, they can be placed close to the AD8177 outputs.
When driving the AD8177 single-endedly, the undriven input is
often terminated with a resistance to balance the input stage.
By terminating the undriven input with a resistor of one-half
the characteristic impedance, the input stage is perfectly balanced
(25 Ω, for example, to balance the two parallel 50 Ω terminations
on the driven input). However, due to the feedback in the input
receiver, there is high speed signal current leaving the undriven
input. To terminate this high speed signal, proper transmission
line techniques should be used.
Finally, the AD8177 pinout allows the user to bring the outputs
out as surface traces to the back-termination resistors. The
designer can avoid creating stubs and reflections by keeping the
AD8177 output signal path on the surface of the board. A stub
is created when a top-to-bottom via connection is made on the
output signal path that is perpendicular to the signal flow.
相關PDF資料
PDF描述
AD8178ABPZ IC VIDEO CROSSPOINT SWIT 676BGA
AD8182ANZ IC MULTIPLEXER DUAL 2X1 14DIP
AD8184AR IC VIDEO MULTIPLEXER 4X1 14SOIC
AD8185ARUZ IC MULTIPLEXER TRPL 2X1 24TSSOP
AD8187ARUZ IC MULTIPLEXER TRPL 2X1 24TSSOP
相關代理商/技術參數(shù)
參數(shù)描述
AD8177-EVALZ 制造商:AD 制造商全稱:Analog Devices 功能描述:500 MHz, Triple 16 】 5 Video Crosspoint Switch
AD8178 制造商:AD 制造商全稱:Analog Devices 功能描述:450 MHz, Triple 16 】 5 Video Crosspoint Switch
AD8178ABPZ 功能描述:IC VIDEO CROSSPOINT SWIT 676BGA RoHS:是 類別:集成電路 (IC) >> 接口 - 模擬開關,多路復用器,多路分解器 系列:- 其它有關文件:STG4159 View All Specifications 標準包裝:5,000 系列:- 功能:開關 電路:1 x SPDT 導通狀態(tài)電阻:300 毫歐 電壓電源:雙電源 電壓 - 電源,單路/雙路(±):±1.65 V ~ 4.8 V 電流 - 電源:50nA 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:7-WFBGA,F(xiàn)CBGA 供應商設備封裝:7-覆晶 包裝:帶卷 (TR)
AD8178ABPZ1 制造商:AD 制造商全稱:Analog Devices 功能描述:450 MHz, Triple 16 】 5 Video Crosspoint Switch
AD8178-EVALZ1 制造商:AD 制造商全稱:Analog Devices 功能描述:450 MHz, Triple 16 】 5 Video Crosspoint Switch