參數(shù)資料
型號(hào)： VCA822IDGS
廠商： Texas Instruments, Inc.
英文描述： Wideband, > 40dB Gain Adjust Range, Linear in V/V VARIABLE GAIN AMPLIFIER
中文描述： 寬帶，“40dB的增益調(diào)整范圍在V，線性音頻/視頻可變?cè)鲆娣糯笃?/td>
文件頁數(shù)： 28/35頁
文件大?。?/td> 837K
代理商： VCA822IDGS
www.ti.com
BOARD LAYOUT
INPUT AND ESD PROTECTION
External
Pin
+V
S
-
V
S
Internal
Circuitry
ESD protection diodes internally
connected to all pins.
VCA822
SBOS343A–SEPTEMBER 2007–REVISED OCTOBER 2007
d) Connections to other wideband devices
on the
board may be made with short direct traces or
through
onboard
transmission
connections, consider the trace and the input to the
next device as a lumped capacitive load. Relatively
wide traces (50mils to 100mils, or 1.27mm to
2.54mm) should be used, preferably with ground and
power planes opened up around them.
Achieving
high-frequency
requires careful attention to printed circuit board
(PCB) layout parasitics and external component
types. Recommendations to optimize performance
include:
optimum
amplifier
performance
such
with
VCA822
a
lines.
For
short
as
the
a) Minimize parasitic capacitance
to any ac ground
for all of the signal I/O pins. This recommendation
includes the ground pin (pin 2). Parasitic capacitance
on the output can cause instability: on both the
inverting input and the noninverting input, it can react
with the source impedance to cause unintentional
band limiting. To reduce unwanted capacitance, a
window around the signal I/O pins should be opened
in all of the ground and power planes around those
pins. Otherwise, ground and power planes should be
unbroken elsewhere on the board. Place a small
series resistance (greater than 25
) with the input pin
connected to ground to help decouple package
parasitics.
e) Socketing a high-speed part like the VCA822 is
not recommended.
The additional lead length and
pin-to-pin capacitance introduced by the socket can
create an extremely troublesome parasitic network,
which can make it almost impossible to achieve a
smooth, stable frequency response. Best results are
obtained by soldering the VCA822 onto the board.
The VCA822 is built using a very high-speed
complementary bipolar process. The internal junction
breakdown voltages are relatively low for these very
small geometry devices. These breakdowns are
reflected in the
Absolute Maximum Ratings
table.
b) Minimize the distance
(less than 0.25”) from the
power-supply
pins
to
decoupling capacitors. At the device pins, the ground
and power plane layout should not be in close
proximity to the signal I/O pins. Avoid narrow power
and ground traces to minimize inductance between
the
pins
and
the
decoupling
power-supply
connections
decoupled with these capacitors. Larger (2.2
μ
F to
6.8
μ
F) decoupling capacitors, effective
frequencies, should also be used on the main supply
pins. These capacitors may be placed somewhat
farther from the device and may be shared among
several devices in the same area of the PCB.
high-frequency
0.1
μ
F
All pins on the VCA822 are internally protected from
ESD
by
means
of
a
reverse-biased diodes to either power supply, as
shown in
Figure 94
. These diodes begin to conduct
when the pin voltage exceeds either power supply by
about 0.7V. This situation can occur with loss of the
amplifier power supplies while a signal source is still
present.
The
diodes
can
continuous current of 30mA without destruction. To
ensure long-term reliability, however, diode current
should be externally limited to 10mA whenever
possible.
pair
of
back-to-back
capacitors.
should
The
be
always
typically
withstand
a
at
lower
c) Careful selection and placement
of external
components
preserve
performance of the VCA822. Resistors should be a
very low reactance type. Surface-mount resistors
work best and allow a tighter overall layout. Metal-film
and carbon composition, axially-leaded resistors can
also
provide
good
high-frequency
Again, keep the leads and PCB trace length as short
as possible. Never use wire-wound type resistors in a
high-frequency application. Because the output pin is
the most sensitive to parasitic capacitance, always
position the series output resistor, if any, as close as
possible
to
the
output
components, such as inverting or non-inverting input
termination resistors, should also be placed close to
the package.
the
high-frequency
performance.
Figure 94. Internal ESD Protection
pin.
Other
network
28
Submit Documentation Feedback
Copyright 2007, Texas Instruments Incorporated
Product Folder Link(s):
VCA822
相關(guān)PDF資料
PDF描述
VCA8613YR 8-Channel VARIABLE GAIN AMPLIFIER
VCB1 3.0 or 5.0 Vdc Option Low Cost 1 to 160 MHz Enable Disable Option TTL/CMOS Compatible
VCB50KM Microcontroller
VCB50KC Microcontroller
VCB50KI Microcontroller
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
VCA822IDGSR 功能描述:運(yùn)算放大器 - 運(yùn)放 WB >40dB Gain Adj Rng Lin V/V Var Gain RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比（最小值）:63 dB 輸入補(bǔ)償電壓:1 mV 輸入偏流（最大值）:10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel
VCA822IDGSRG4 功能描述:運(yùn)算放大器 - 運(yùn)放 WB >40dB Gain Adj Rng Lin V/V Var Gain RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比（最小值）:63 dB 輸入補(bǔ)償電壓:1 mV 輸入偏流（最大值）:10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel
VCA822IDGST 功能描述:運(yùn)算放大器 - 運(yùn)放 WB >40dB Gain Adj Rng Lin V/V Var Gain RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比（最小值）:63 dB 輸入補(bǔ)償電壓:1 mV 輸入偏流（最大值）:10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel
VCA822IDGSTG4 功能描述:運(yùn)算放大器 - 運(yùn)放 WB >40dB Gain Adj Rng Lin V/V Var Gain RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比（最小值）:63 dB 輸入補(bǔ)償電壓:1 mV 輸入偏流（最大值）:10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel
VCA822IDR 功能描述:運(yùn)算放大器 - 運(yùn)放 WB >40dB Gain Adj Rng Lin V/V Var Gain RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比（最小值）:63 dB 輸入補(bǔ)償電壓:1 mV 輸入偏流（最大值）:10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*