參數資料
| 型號： | AD8177ABPZ |
| 廠商： | Analog Devices Inc |
| 文件頁數： | 19/40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 |
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AD8177
Rev. 0 | Page 26 of 40
THEORY OF OPERATION
The AD8177 is a nonblocking crosspoint with 16 differential
RGB input channels and 5 differential RGB output channels.
Although the AD8177 is primarily meant for differential-in,
differential-out, middle-of-Cat-5-run applications, each differ-
ential RGB output channel is complemented by H and V syncs
for use in end-of-Cat-5-run, single-ended output applications.
Processing of common-mode (CM) voltage levels is achieved by
placing the AD8177 in either of its two operation modes. In the
first operation mode (CMENC low), the input CM of each RGB
differential pair (possibly present either in the form of sync-on
CM signaling or noise) is removed through the switch, and the
output CM is set to a global reference voltage via the VOCM_
CMENCOFF analog input. Therefore, the AD8177 can behave
as a differential-in, differential-out switch. If sync-on CM signaling
is present at the differential RGB inputs, then the H and V outputs
represent decoded syncs. In the second operation mode, input
sync-on CM signaling is propagated through the switch. Note
that in this mode, as in the previous one, the overall input CM
is blocked through the switch. In this mode, the overall output
CM is set to a global reference voltage via the VOCM_CMENCON
analog input.
In either operation mode, input pin VBLK defines the black
level of the positive output phase. The combination of VBLK
and VOCM_CMENCOFF allows the user to position the positive
and negative output phases anywhere in the allowable output
voltage range.
The switch is organized into five 16:1 RGB multiplexers, with each
being responsible for connecting an RGB input channel to its
respective RGB output channel. Decoding logic selects a single
input (or none) in each multiplexer and connects it to its respective
output. Feedback around each multiplexer realizes a closed-
loop differential-in, differential-out gain of +2. A second loop
realizes a closed-loop common-mode-in gain of +1.
Each differential RGB input channel is buffered by a differential
receiver, which is capable of accepting input CM voltages extending
all the way to either supply rail. In addition to passing differential
information, each receiver processes and routes input CM
voltages. Excess closed-loop receiver bandwidth reduces the
receiver’s effect on the overall device bandwidth.
The output stage is designed for fast slew rate and settling time
while driving a series-terminated Cat-5 cable. Unlike competing
multiplexer designs, the small signal bandwidth closely
approaches the large signal bandwidth.
The outputs of the AD8177 can be disabled to minimize on-
chip power dissipation. When disabled, there is a feedback
network of approximately 2.7 kΩ between the differential outputs.
This high impedance allows multiple ICs to be bussed together
without additional buffering. Care must be taken to reduce
output capacitance, which can result in overshoot and frequency-
domain peaking. A series of internal amplifiers drive internal
nodes such that wideband high impedance is presented at the
disabled output, even while the output bus experiences fast signal
swings. When the outputs are disabled and driven externally, the
voltage applied to them should not exceed the valid output
swing range for the AD8177 to keep these internal amplifiers
in their linear range of operation. Applying excessive differential
voltages to the disabled outputs can cause damage to the AD8177
and should be avoided (see the Absolute Maximum Ratings
section of this data sheet for guidelines).
The connectivity of the AD8177 is controlled by a flexible TTL-
compatible logic interface. Either parallel or serial loading into
a first rank of latches preprograms each output. A global update
signal moves the programming data into the second rank of
latches, simultaneously updating all outputs. In serial mode,
a serial-out pin allows devices to be daisy-chained together for
single-pin programming of multiple ICs. A power-on reset pin
is available to avoid bus conflicts by disabling all outputs. This
power-on reset clears the second rank of latches but does not
clear the first rank of latches. In serial mode, preprogramming
individual inputs is not possible and the entire shift register needs
to be flushed. A global chip-select pin gates the input clock and
the global update signal to the second rank of buffers.
The AD8177 can operate on a single 5 V supply, powering both
the signal path (with the VPOS/VNEG supply pins) and the
control logic interface (with the VDD/DGND supply pins).
Split supply operation is possible with ±2.5 V supplies to easily
interface to ground-referenced video signals. In this case,
a flexible logic interface allows the control logic supplies
(VDD/DGND) to be run off 5 V/0 V to 3.3 V/0 V, and the
analog core remains on split supplies. Additional flexibility in
the analog output common-mode level (VOCM_CMENCOFF)
and output black level (VBLK) facilitates operation with unequally
split supplies. If +3 V/2 V supplies to +2 V/3 V supplies are
desired, the output CM can still be set to 0 V for ground-referenced
video signals.
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相關代理商/技術參數 |
參數描述 |
|---|---|
| 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，FCBGA 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 |
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