参数资料
| 型号： | AD8176ABPZ |
| 厂商： | Analog Devices Inc |
| 文件页数： | 25/40页 |
| 文件大小： | 0K |
| 描述： | IC VIDEO CROSSPOINT SWIT 676BGA |
| 标准包装： | 1 |
| 功能： | 视频交叉点开关 |
| 电路： | 3 x 16:9 |
| 电压电源： | 单/双电源 |
| 电压 - 电源，单路/双路(±)： | 4.5 V ~ 5.5 V，±2.5V |
| 电流 - 电源： | 600mA |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 676-BGA |
| 供应商设备封装： | 676-BGA（27x27） |
| 包装： | 管件 |
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AD8176
Rev. 0 | Page 31 of 40
split supplies). Adjusting the output common-mode voltage
beyond ±0.5 V can limit differential swing internally below the
specifications on the data sheet. The overall common-mode of
the output voltages follow the voltage applied to VOCM_
CMENCON or VCOM_CMENCOFF, implying a gain of +1.
Likewise, sync-on common-mode signaling is carried through
the AD8176 (CMENC must be in its high state), implying a gain
of +1 for this path as well.
The common-mode reference pins are analog signal inputs,
common to all output stages on the device. They require only
small amounts of bias current, but noise appearing on these
pins is buffered to all the output stages. As such, they should
be connected to low noise, low impedance voltage references
to avoid being sources of noise, offset, and crosstalk in the
signal path.
Termination
The AD8176 is designed to drive 100 Ω terminated to ground
on each output (or an effective 200 Ω differential) while
meeting data sheet specifications over the specified operating
temperature range, if care is taken to observe the maximum
power derating curves.
Termination at the load end is recommended to shorten settling
time and for best signal integrity. In differential signal paths, it
is often desirable to series-terminate the outputs, with a resistor
in series with each output. A side effect of termination is an
attenuation of the output signal by a factor of two. In this case,
gain is usually necessary somewhere else in the signal path to
restore the signal level.
Whenever a differential output is used single-ended, it is
desirable to terminate the used single-ended output with a
series resistor, as well as to place a resistor on the unused output
to match the load seen by the used output.
When disabled, the outputs float to midsupply. A small current
is required to drive the outputs away from their midsupply
state. This current is easily provided by an AD8176 output (in
its enabled state) bussed together with the disabled output.
Exceeding the allowed output voltage range may saturate
internal nodes in the disabled output, and consequently an
increase in disabled output current may be observed.
Single-Ended Output
Usage
The AD8176 output pairs can be used single-ended, taking
only one output and not using the second. This is often desired
to reduce the routing complexity in the design, or because a
single-ended load is being driven directly. This mode of opera-
tion produces good results, but has some shortcomings when
compared to taking the output differentially. When observing
the single-ended output, noise that is common to both outputs
appears in the output signal.
When observing the output single-ended, the distribution
of offset voltages appear greater. In the differential case, the
difference between the outputs when the difference between
the inputs is zero is a small differential offset. This offset is
created from mismatches in devices in the signal path. In the
single-ended case, this differential offset is still observed, but
an additional offset component is also relevant. This additional
component is the common-mode offset, which is the difference
between the average of the outputs and the output common-
mode reference. This offset is created by mismatches that affect
the signal path in a common-mode manner. A differential
receiver rejects this common-mode offset voltage, but in the
single-ended case, this offset is observed with respect to the
signal ground. The single-ended output sums half the differential
offset voltage and all of the common-mode offset voltage for a
net increase in observed offset.
Single-Ended Gain
The AD8176 operates as a closed-loop differential amplifier.
The primary control loop forces the difference between the
output terminals to be a ratio of the difference between the
input terminals. One output increases in voltage, while the
other decreases an equal amount to make the total output
voltage difference correct. The average of these output voltages
is forced to the voltage on the common-mode reference
terminal (VOCM_CMENCOFF or VOCM_CMENCON) by a
second control loop. If only one output terminal is observed
with respect to the common-mode reference terminal, only half
of the difference voltage will be observed. This implies that
when using only one output of the device, half of the differential
gain is observed. An AD8176 taken with single-ended output
appears to have a gain of +2.
It is important to note that all considerations applying to the
used output phase regarding output voltage headroom, apply
unchanged to the complement output phase even if this is not
actually used.
Termination
When operating the AD8176 with a single-ended output, the
preferred output termination scheme is to refer the load to the
output common-mode. A series-termination can be used, at an
additional cost of one half the signal gain.
In single-ended output operation, the complementary phase of
the output is not used, and may or may not be terminated
locally. Although the unused output can be floated to reduce
power dissipation, there are several reasons for terminating the
unused output with a load resistance matched to the load on the
signal output.
One component of crosstalk is magnetic coupling by mutual
inductance between output package traces and bond wires that
carry load current. In a differential design, there is coupling
from one pair of outputs to other adjacent pairs of outputs. The
differential nature of the output signal simultaneously drives the
coupling field in one direction for one phase of the output, and
in an opposite direction for the other phase of the output. These
相关PDF资料 |
PDF描述 |
|---|---|
| AD8177ABPZ | IC VIDEO CROSSPOINT SWIT 676BGA |
| AD8178ABPZ | IC VIDEO CROSSPOINT SWIT 676BGA |
| AD8182ANZ | IC MULTIPLEXER DUAL 2X1 14DIP |
| AD8184AR | IC VIDEO MULTIPLEXER 4X1 14SOIC |
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相关代理商/技术参数 |
参数描述 |
|---|---|
| AD8176-EVAL | 制造商:AD 制造商全称:Analog Devices 功能描述:475 MHz, Triple 16 】 9 Video Crosspoint Switch |
| AD8177 | 制造商:AD 制造商全称:Analog Devices 功能描述:500 MHz, Triple 16 】 5 Video Crosspoint Switch |
| AD8177ABPZ | 功能描述:IC VIDEO CROSSPOINT SWIT 676BGA RoHS:是 类别:集成电路 (IC) >> 接口 - 模拟开关，多路复用器，多路分解器 系列:- 其它有关文件:STG4159 View All Specifications 标准包装:5,000 系列:- 功能:开关 电路:1 x SPDT 导通状态电阻:300 毫欧 电压电源:双电源 电压 - 电源，单路/双路(±):±1.65 V ~ 4.8 V 电流 - 电源:50nA 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:7-WFBGA，FCBGA 供应商设备封装:7-覆晶 包装:带卷 (TR) |
| AD8177-EVALZ | 制造商:AD 制造商全称:Analog Devices 功能描述:500 MHz, Triple 16 】 5 Video Crosspoint Switch |
| AD8178 | 制造商:AD 制造商全称:Analog Devices 功能描述:450 MHz, Triple 16 】 5 Video Crosspoint Switch |
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