參數資料
型號: AD8001AQ
廠商: ANALOG DEVICES INC
元件分類: 運動控制電子
英文描述: 800 MHz, 50 mW Current Feedback Amplifier
中文描述: OP-AMP, 9000 uV OFFSET-MAX, CDIP8
封裝: CERDIP-8
文件頁數: 10/16頁
文件大?。?/td> 222K
代理商: AD8001AQ
REV. C
AD8001
–10–
THEORY OF OPERATION
A very simple analysis can put the operation of the AD8001, a
current feedback amplifier, in familiar terms. Being a current
feedback amplifier, the AD8001’s open-loop behavior is ex-
pressed as transimpedance,
V
O
/
I
–IN
, or T
Z
. The open-loop
transimpedance 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 R
IN
is proportional to 1/g
M
, the equivalent voltage
gain is just T
Z
×
g
M
, where the g
M
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 40, basic
analysis yields the following result.
V
V
G
T
S
×
T
G
R
R
G
R
R
R
g
O
IN
Z
Z
IN
IN
M
=
×
+
+
=
+
=
( )
(S
/
1
1
1
2
1
50
Recognizing that
G
×
R
IN
<<
R
1 for low gains, it can be seen to
the first order that bandwidth for this amplifier is independent
of gain (G). This simple analysis in conjunction with Figure 41
can, in fact, predict the behavior of the AD8001 over a wide
range of conditions.
V
OUT
R1
R2
R
IN
V
IN
Figure 40.
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 Pin 2 will also add phase in the feedback
loop, so picking an optimum value for R
F
can be difficult. Fig-
ure 42 illustrates this problem. Here the fine scale (0.1 dB/div)
flatness is plotted vs feedback resistance. These plots were taken
using an evaluation card which is available to customers so that
these results may readily be duplicated (see Evaluation Board
section).
Achieving and maintaining gain flatness of better than 0.1 dB at
frequencies above 10 MHz requires careful consideration of
several issues.
FREQUENCY – Hz
1M
10
100k
1M
1G
100M
10M
100
100k
10k
1k
T
Z
V
Figure 41. Transimpedance vs. Frequency
O
0.1
0
–0.9
1M
10M
100M
–0.1
–0.2
–0.3
–0.4
–0.5
FREQUENCY – Hz
–0.6
–0.7
–0.8
G = +2
R
F
=
649
V
R
F
= 698
V
R
F
= 750
V
Figure 42. 0.1 dB Flatness vs. Frequency
Choice of Feedback and Gain Resistors
Because of the above-mentioned relationship between the band-
width and feedback resistor, 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 associ-
ated parasitic capacitance and inductance. Surface mount resis-
tors were used for the bulk of the characterization for this data
sheet. It is not recommended that leaded components be used
with the AD8001.
相關PDF資料
PDF描述
AD8001AR 800 MHz, 50 mW Current Feedback Amplifier
AD8001AR-REEL 800 MHz, 50 mW Current Feedback Amplifier
AD8001AR-REEL7 800 MHz, 50 mW Current Feedback Amplifier
AD8001ART-REEL MB 32C 32#20 PIN PLUG
AD8001ART-REEL7 MB 32C 32#20 SKT PLUG
相關代理商/技術參數
參數描述
AD8001AR 功能描述:IC OPAMP CF LP LDIST 70MA 8SOIC RoHS:否 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標準包裝:150 系列:- 放大器類型:音頻 電路數:2 輸出類型:- 轉換速率:5 V/µs 增益帶寬積:12MHz -3db帶寬:- 電流 - 輸入偏壓:100nA 電壓 - 輸入偏移:500µV 電流 - 電源:6mA 電流 - 輸出 / 通道:50mA 電壓 - 電源,單路/雙路(±):4 V ~ 32 V,±2 V ~ 16 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-TSSOP(0.173",4.40mm 寬) 供應商設備封裝:8-TSSOP 包裝:管件
AD8001AR-REEL 功能描述:IC OPAMP CF LP LDIST 70MA 8SOIC RoHS:否 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標準包裝:73 系列:Over-The-Top® 放大器類型:通用 電路數:4 輸出類型:滿擺幅 轉換速率:0.07 V/µs 增益帶寬積:200kHz -3db帶寬:- 電流 - 輸入偏壓:1nA 電壓 - 輸入偏移:285µV 電流 - 電源:50µA 電流 - 輸出 / 通道:25mA 電壓 - 電源,單路/雙路(±):2 V ~ 44 V,±1 V ~ 22 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:16-WFDFN 裸露焊盤 供應商設備封裝:16-DFN-EP(5x3) 包裝:管件
AD8001AR-REEL7 功能描述:IC OPAMP CF LP LDIST 70MA 8SOIC RoHS:否 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標準包裝:50 系列:- 放大器類型:J-FET 電路數:2 輸出類型:- 轉換速率:13 V/µs 增益帶寬積:3MHz -3db帶寬:- 電流 - 輸入偏壓:65pA 電壓 - 輸入偏移:3000µV 電流 - 電源:1.4mA 電流 - 輸出 / 通道:- 電壓 - 電源,單路/雙路(±):7 V ~ 36 V,±3.5 V ~ 18 V 工作溫度:-40°C ~ 85°C 安裝類型:通孔 封裝/外殼:8-DIP(0.300",7.62mm) 供應商設備封裝:8-PDIP 包裝:管件
AD8001ART 制造商:AD 制造商全稱:Analog Devices 功能描述:800 MHz 50 mW Current Feedback Amplifier(222.93 k)
AD8001ART-EBZ 功能描述:放大器 IC 開發(fā)工具 AD8001ART-EBZ_A00674_EB-O5/6RT-1Z RoHS:否 制造商:International Rectifier 產品:Demonstration Boards 類型:Power Amplifiers 工具用于評估:IR4302 工作電源電壓:13 V to 23 V