データシートサーチシステム
  Japanese  ▼
ALLDATASHEET.JP

X  

AD8002AR-REEL7 データシート(PDF) 10 Page - Analog Devices

部品番号 AD8002AR-REEL7
部品情報  Dual 600 MHz, 50 mW Current Feedback Amplifier
Download  20 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
メーカー  AD [Analog Devices]
ホームページ  http://www.analog.com
Logo AD - Analog Devices

AD8002AR-REEL7 データシート(HTML) 10 Page - Analog Devices

Back Button AD8002AR-REEL7 Datasheet HTML 6Page - Analog Devices AD8002AR-REEL7 Datasheet HTML 7Page - Analog Devices AD8002AR-REEL7 Datasheet HTML 8Page - Analog Devices AD8002AR-REEL7 Datasheet HTML 9Page - Analog Devices AD8002AR-REEL7 Datasheet HTML 10Page - Analog Devices AD8002AR-REEL7 Datasheet HTML 11Page - Analog Devices AD8002AR-REEL7 Datasheet HTML 12Page - Analog Devices AD8002AR-REEL7 Datasheet HTML 13Page - Analog Devices AD8002AR-REEL7 Datasheet HTML 14Page - Analog Devices Next Button
Zoom Inzoom in Zoom Outzoom out
 10 / 20 page
background image
REV. D
AD8002
–10–
THEORY OF OPERATION
A very simple analysis can put the operation of the AD8002, a
current feedback amplifier, in familiar terms. Being a current
feedback amplifier, the AD8002’s open-loop behavior is expressed
as transimpedance,
∆VO/∆I–IN, or TZ. The open-loop transim-
pedance behaves just as the open-loop voltage gain of a voltage
feedback amplifier, that is, it has a large dc value and decreases
at roughly 6 dB/octave in frequency.
Since the RIN is proportional to 1/gm, the equivalent voltage
gain is just TZ
× g
m, where the gm in question is the trans-
conductance of the input stage. This results in a low open-loop
input impedance at the inverting input, a now familiar result.
Using this amplifier as a follower with gain, Figure 4, basic
analysis yields the following result.
V
V
G
TS
TS
G
R
R
G
R
R
Rg
O
IN
Z
ZIN
IN
m
+
=+
=
()
()
/
1
1
1
2
150
VOUT
R1
R2
RIN
VIN
Figure 4.
Recognizing that G
× R
IN << R1 for low gains, it can be seen to
the first order that bandwidth for this amplifier is independent
of gain (G).
Considering that additional poles contribute excess phase at
high frequencies, there is a minimum feedback resistance below
which peaking or oscillation may result. This fact is used to
determine the optimum feedback resistance, R F. In practice
parasitic capacitance at the inverting input terminal will also add
phase in the feedback loop, so picking an optimum value for RF
can be difficult.
Achieving and maintaining gain flatness of better than 0.1 dB at
frequencies above 10 MHz requires careful consideration of
several issues.
Choice of Feedback and Gain Resistors
The fine scale gain flatness will, to some extent, vary with
feedback resistance. It, therefore, is recommended that once
optimum resistor values have been determined, 1% tolerance
values should be used if it is desired to maintain flatness over a
wide range of production lots. In addition, resistors of different
construction have different associated parasitic capacitance
and inductance. Surface mount resistors were used for the bulk
of the characterization for this data sheet. It is not recommended
that leaded components be used with the AD8002.
Printed Circuit Board Layout Considerations
As expected for a wideband amplifier, PC board parasitics can
affect the overall closed-loop performance. Of concern are
stray capacitances at the output and the inverting input nodes. If
a ground plane is to be used on the same side of the board as
the signal traces, a space (5 mm min) should be left around the
signal lines to minimize coupling. Additionally, signal lines
connecting the feedback and gain resistors should be short
enough so that their associated inductance does not cause high
frequency gain errors. Line lengths on the order of less than
5 mm are recommended. If long runs of coaxial cable are being
driven, dispersion and loss must be considered.
Power Supply Bypassing
Adequate power supply bypassing can be critical when optimiz-
ing the performance of a high-frequency circuit. Inductance in
the power supply leads can form resonant circuits that produce
peaking in the amplifier’s response. In addition, if large current
transients must be delivered to the load, bypass capacitors
(typically greater than 1
µF) will be required to provide the
best settling time and lowest distortion. A parallel combina-
tion of 4.7
µF and 0.1 µF is recommended. Some brands of
electrolytic capacitors will require a small series damping resis-
tor
≈4.7 Ω for optimum results.
DC Errors and Noise
There are three major noise and offset terms to consider in a
current feedback amplifier. For offset errors, refer to the equa-
tion below. For noise error, the terms are root-sum-squared to
give a net output error. In the circuit shown in Figure 5 they
are input offset (VIO), which appears at the output multiplied by
the noise gain of the circuit (1 + R F/RI), noninverting input
current (IBN
× RN), also multiplied by the noise gain, and the
inverting input current, which, when divided between RF and RI
and subsequently multiplied by the noise gain, always appears
at the output as IBN
× RF. The input voltage noise of the AD8002
is a low 2 nV/
√Hz. At low gains, though, the inverting input
current noise times RF is the dominant noise source. Careful
layout and device matching contribute to better offset and
drift specifications for the AD8002 compared to many other
current feedback amplifiers. The typical performance curves in
conjunction with the equations below can be used to predict the
performance of the AD8002 in any application.
VV
R
R
IR
R
R
IR
OUT
IO
F
I
BN
N
F
I
BI
F
+
 ±×
×
+
 ±×
11
RF
RI
RN
IBN
VOUT
IBI
Figure 5. Output Offset Voltage


同様の部品番号 - AD8002AR-REEL7

メーカー部品番号データシート部品情報
logo
Analog Devices
AD8002AR-REEL7 AD-AD8002AR-REEL7 Datasheet
351Kb / 18P
   Dual 600 MHz, 50 mW Current Feedback Amplifier
REV. C
AD8002AR-REEL7 AD-AD8002AR-REEL7 Datasheet
372Kb / 20P
   Dual 600 MHz, 50 mW Current Feedback Amplifier
REV. D
AD8002AR-REEL7 AD-AD8002AR-REEL7 Datasheet
556Kb / 21P
   Dual 600 MHz, 50 mW Current Feedback Amplifier
REV. D
More results

同様の説明 - AD8002AR-REEL7

メーカー部品番号データシート部品情報
logo
Analog Devices
AD8002 AD-AD8002_01 Datasheet
372Kb / 20P
   Dual 600 MHz, 50 mW Current Feedback Amplifier
REV. D
AD8002 AD-AD8002 Datasheet
351Kb / 18P
   Dual 600 MHz, 50 mW Current Feedback Amplifier
REV. C
AD8002ARZ AD-AD8002ARZ Datasheet
373Kb / 20P
   Dual 600 MHz, 50 mW Current Feedback Amplifier
REV. D
AD8002ANZ AD-AD8002ANZ Datasheet
556Kb / 21P
   Dual 600 MHz, 50 mW Current Feedback Amplifier
REV. D
AD8002 AD-AD8002_15 Datasheet
590Kb / 21P
   Dual 600 MHz, 50 mW Current Feedback Amplifier
REV. D
AD8001ANZ AD-AD8001ANZ Datasheet
562Kb / 17P
   800 MHz, 50 mW Current Feedback Amplifier
REV. D
AD8001 AD-AD8001 Datasheet
222Kb / 16P
   800 MHz, 50 mW Current Feedback Amplifier
REV. C
AD8001ARTZ-REEL7 AD-AD8001ARTZ-REEL7 Datasheet
388Kb / 16P
   800 MHz, 50 mW Current Feedback Amplifier
REV. D
AD8001 AD-AD8001_15 Datasheet
562Kb / 17P
   800 MHz, 50 mW Current Feedback Amplifier
REV. D
AD8001 AD-AD8001_03 Datasheet
335Kb / 16P
   800 MHz, 50 mW Current Feedback Amplifier
REV. D
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20


データシート ダウンロード

Go To PDF Page


リンク URL




プライバシーポリシー
ALLDATASHEET.JP
ALLDATASHEETはお客様のビジネスに役立ちますか?  [ DONATE ] 

Alldatasheetは   |   広告   |   お問い合わせ   |   プライバシーポリシー   |   リンク交換   |   メーカーリスト
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com