- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄375243 > AD8310 (Analog Devices, Inc.) Fast, Voltage-Out DC-440 MHz 95 dB Logarithmic Amplifier PDF資料下載
參數(shù)資料
| 型號(hào)： | AD8310 |
| 廠商： | Analog Devices, Inc. |
| 元件分類： | 運(yùn)動(dòng)控制電子 |
| 英文描述： | Fast, Voltage-Out DC-440 MHz 95 dB Logarithmic Amplifier |
| 中文描述： | 快速，電壓輸出的DC - 440 MHz的95分貝數(shù)放大器 |
| 文件頁(yè)數(shù)： | 14/16頁(yè) |
| 文件大?。?/td> | 323K |
| 代理商： | AD8310 |
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)當(dāng)前第14頁(yè)第15頁(yè)第16頁(yè)
AD8310
–14–
REV. A
V
(2.7–5.5V)
0.01
m
F
52.3
V
NC = NO CONNECT
C1
0.01
m
F
NC
INHI ENBL
BFIN VPOS
INLO COMM OFLT VOUT
1
2
AD8310
4.7
V
V
OUT
100mV/dB
SIGNAL
INPUT
C2
0.01
m
F
R
12.1k
V
3
4
8
7
6
5
Figure 32. Raising the Slope to 100 mV/dB
Output Filtering
In applications where maximum video bandwidth (and conse-
quently fast rise time) is desired, it is essential that the BFIN pin
be left unconnected and free of any stray capacitance.
The nominal output video bandwidth of 25 MHz, can be reduced
by connecting a ground-referenced capacitor (C
FILT
) to the BFIN
pin as shown in Figure 33. This is generally done to reduce output
ripple (at twice the input frequency for a symmetric input wave-
form such as sinusoidal signals).
C
FILT
is selected using the equation
C
FILT
=
1/(2
π
×
3
k
×
Video Bandwidth
) –2.1 pF
The
Video Bandwidth
should typically be set at a frequency equal
to about one-tenth the minimum input frequency. This will
ensure that the output ripple of the demodulated log output, which
is at twice the input frequency, will be well filtered.
In many applications of log amps, it may be necessary to lower
the corner frequency of the post-demodulation filtering, in order
to achieve low output ripple while maintaining a rapid response
time to changes in signal level. An example of a four-pole active
filter is shown the AD8307 data sheet.
+4
2
m
A/dB
3k
V
V
OUT
BFIN
C
FILT
AD8310
C
FILT
= 1/(2
p
3
3k
V
3
VIDEO BANDWIDTH) – 2.1pF
Figure 33. Lowering the Post-Demodulation Video
Bandwidth
Lowering the High-Pass Corner Frequency of the Offset
Compensation Loop
In normal operation, using an AC-coupled input signal, the
OFLT pin should be left unconnected. Input-referred dc offsets
of about 1.5 mV in the signal path are nulled via an internal
offset control loop. This loop has a
high-pass
–3 dB corner at
about 2 MHz. In low frequency ac-coupled applications, it is
necessary to lower this corner frequency to prevent input signals
from being misinterpreted as offsets. An external capacitor on
OFLT will lower the high-pass corner to arbitrarily low frequencies
(Figure 34). For example, by using 1
μ
F capacitor, the 3 dB
corner will be reduced to 60 Hz.
The corner frequency is set by the equation
F
CORNER
= 1/(2
π
×
2625
×
C
OFLT
)
where
C
OFLT
is the capacitor connected to OFLT.
C
(SEE TEXT)
AD8310
OFLT
Figure 34. Lowering the High-Pass Corner Frequency of
the Offset Control Loop
APPLICATIONS
The AD8310 is highly versatile and easy to use. Being complete,
it needs only a few external components, and most can be
immediately accommodated by using the simple connections
shown in the preceding section. A few examples of more special-
ized applications are provided here; see also the AD8307 data
sheet for further applications; note the slightly different pinout.
Cable-Driving
The AD8310 is capable of driving a grounded 100
load to 2.5 V,
for a supply voltage of 3 V or greater. If reverse-termination is
required when driving a 50
cable, it should be included in
series with the output, as shown in Figure 35. The slope at the
load will then be 12 mV/dB. In some cases, it may be permis-
sible to operate the cable without a termination at the far end,
in which case the slope will not be lowered. Where a further
increase in slope is desirable, the scheme shown in Figure 32
may be used.
AD8310
VOUT
50
V
50
V
Figure 35. Output Response of Cable-Driver Application
DC-Coupled Input
It may occasionally be necessary to provide response to dc
inputs. Since the AD8310 is internally dc-coupled, there is no
fundamental reason why this is precluded. However, there is a
practical constraint, which is that its differential inputs must be
positioned at least 2 V above the COM potential for proper
biasing of the first stage. Usually, the source will be a single-sided
ground-referenced signal, so it will thus be necessary to provide
level-shifting and a single-ended-to-differential conversion to
correctly drive the AD8310’s inputs.
Figure 36 shows how a level-shift to midsupply (2.5 V in this
example) and a single-ended-to-differential conversion can be
accomplished using the AD8138 differential amplifier. The four
499
resistors set up a gain of unity. An output common-mode
(or bias) voltage of 2.5 is achieved by applying 2.5 V (from a
supply-referenced resistive divider) to the AD8138’s VOCM
pin. The differential outputs of the AD8138 directly drive the
1.1 k
input impedance of the AD8310.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| AD8310-EVAL | Fast, Voltage-Out DC-440 MHz 95 dB Logarithmic Amplifier |
| AD8310ARM | Fast, Voltage-Out DC-440 MHz 95 dB Logarithmic Amplifier |
| AD8310ARM-REEL | Fast, Voltage-Out DC-440 MHz 95 dB Logarithmic Amplifier |
| AD8310ARM-REEL7 | Fast, Voltage-Out DC-440 MHz 95 dB Logarithmic Amplifier |
| AD8315 | 50 dB GSM PA Controller |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| AD8310_05 | 制造商:AD 制造商全稱:Analog Devices 功能描述:Fast, Voltage-Out DC-440 MHz, 95 dB Logarithmic Amplifier |
| AD8310ARM | 功能描述:IC LOGARITHMIC AMP 95DB 8-MSOP RoHS:否 類別:集成電路 (IC) >> 線性 - 放大器 - 專用 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:60 系列:- 類型:可變?cè)鲆娣糯笃?應(yīng)用:CATV 安裝類型:表面貼裝 封裝/外殼:20-WQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:20-TQFN-EP（5x5） 包裝:托盤 |
| AD8310ARM-REEL | 制造商:Analog Devices 功能描述:SP Amp LOG Amp Single R-R I/P 5.5V 8-Pin MSOP T/R |
| AD8310ARM-REEL7 | 功能描述:IC LOGARITHMIC AMP 8-MSOP T/R RoHS:否 類別:集成電路 (IC) >> 線性 - 放大器 - 專用 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:60 系列:- 類型:可變?cè)鲆娣糯笃?應(yīng)用:CATV 安裝類型:表面貼裝 封裝/外殼:20-WQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:20-TQFN-EP（5x5） 包裝:托盤 |
| AD8310ARMZ | 功能描述:IC LOGARITHMIC AMP 95DB 8-MSOP RoHS:是 類別:集成電路 (IC) >> 線性 - 放大器 - 專用 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:60 系列:- 類型:可變?cè)鲆娣糯笃?應(yīng)用:CATV 安裝類型:表面貼裝 封裝/外殼:20-WQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:20-TQFN-EP（5x5） 包裝:托盤 |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。