- 您現在的位置：買賣IC網 > PDF目錄373954 > AD8656ARZ-REEL7 (ANALOG DEVICES INC) Low Noise, Precision CMOS Amplifier PDF資料下載
參數資料
| 型號： | AD8656ARZ-REEL7 |
| 廠商： | ANALOG DEVICES INC |
| 元件分類： | 運動控制電子 |
| 英文描述： | Low Noise, Precision CMOS Amplifier |
| 中文描述： | DUAL OP-AMP, 550 uV OFFSET-MAX, 28 MHz BAND WIDTH, PDSO8 |
| 封裝： | LEAD FREE, MS-012AA, SOIC-8 |
| 文件頁數： | 16/20頁 |
| 文件大小： | 273K |
| 代理商： | AD8656ARZ-REEL7 |
AD8655/AD8656
APPLICATIONS
INPUT OVERVOLTAGE PROTECTION
The internal protective circuitry of the AD8655/AD8656 allows
voltages exceeding the supply to be applied at the input. It is
recommended, however, not to apply voltages that exceed the
supplies by more than 0.3 V at either input of the amplifier. If a
higher input voltage is applied, series resistors should be used to
limit the current flowing into the inputs. The input current
should be limited to less than 5 mA.
Rev. A | Page 16 of 20
One simple technique for compensation is a snubber that
consists of a simple RC network. With this circuit in place,
output swing is maintained, and the amplifier is stable at all
gains.
Figure 57 shows the implementation of a snubber, which
reduces overshoot by more than 30% and eliminates ringing.
Using a snubber does not recover the loss of bandwidth
incurred from a heavy capacitive load.
TIME (2
μ
s/DIV)
V
S
= ±2.5V
A
V
= 1
C
L
= 500pF
0
V
The extremely low input bias current allows the use of larger
resistors, which allows the user to apply higher voltages at the
inputs. The use of these resistors adds thermal noise, which
contributes to the overall output voltage noise of the amplifier.
For example, a 10 kΩ resistor has less than 12.6 nV/√Hz of
thermal noise and less than 10 nV of error voltage at room
temperature.
INPUT CAPACITANCE
Along with bypassing and ground, high speed amplifiers can be
sensitive to parasitic capacitance between the inputs and ground.
For circuits with resistive feedback network, the total capacitance,
whether it is the source capacitance, stray capacitance on the
input pin, or the input capacitance of the amplifier, causes a
breakpoint in the noise gain of the circuit. As a result, a
capacitor must be added in parallel with the gain resistor to
obtain stability. The noise gain is a function of frequency and
peaks at the higher frequencies, assuming the feedback capaci-
tor is selected to make the second-order system critically
damped. A few picofarads of capacitance at the input reduce
the input impedance at high frequencies, which increases the
amplifier’s gain, causing peaking in the frequency response or
oscillations. With the AD8655/AD8656, additional input
damping is required for stability with capacitive loads greater
than 200 pF with direct input to output feedback. See the
Driving Capacitive Loads section.
Figure 56. Driving Heavy Capacitive Loads Without Compensation
V+
200
Ω
500pF
500pF
V–
V
CC
V
EE
200mV
+
–
0
+
–
Figure 57. Snubber Network
V
S
= ±2.5V
A
V
= 1
R
S
= 200
Ω
C
S
= 500pF
C
L
= 500pF
TIME (10
μ
s/DIV)
0
V
DRIVING CAPACITIVE LOADS
Although the AD8655/AD8656 can drive capacitive loads up to
500 pF without oscillating, a large amount of ringing is present
when operating the part with input frequencies above 100 kHz.
This is especially true when the amplifiers are configured in
positive unity gain (worst case). When such large capacitive
loads are required, the use of external compensation is highly
recommended. This reduces the overshoot and minimizes
ringing, which, in turn, improves the stability of the
AD8655/AD8656 when driving large capacitive loads.
Figure 58. Driving Heavy Capacitive Loads Using a Snubber Network
相關PDF資料 |
PDF描述 |
|---|---|
| AD8655 | Low Noise, Precision CMOS Amplifier |
| AD8655ARMZ-R2 | Low Noise, Precision CMOS Amplifier |
| AD8655ARMZ-REEL | Low Noise, Precision CMOS Amplifier |
| AD8661ACP | 16V Low Cost, High Performance CMOS Rail-to-Rail Operational Amplifiers |
| AD8661ARZ | 16V Low Cost, High Performance CMOS Rail-to-Rail Operational Amplifiers |
相關代理商/技術參數 |
參數描述 |
|---|---|
| AD8656WARMZ-REEL | 功能描述:IC OPAMP GP R-R CMOS 28MHZ 8MSOP RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:DigiTrim® 標準包裝:1,000 系列:- 放大器類型:電壓反饋 電路數:4 輸出類型:滿擺幅 轉換速率:33 V/µs 增益帶寬積:20MHz -3db帶寬:30MHz 電流 - 輸入偏壓:2nA 電壓 - 輸入偏移:3000µV 電流 - 電源:2.5mA 電流 - 輸出 / 通道:30mA 電壓 - 電源，單路/雙路(±):4.5 V ~ 16.5 V，±2.25 V ~ 8.25 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:14-SOIC（0.154"，3.90mm 寬） 供應商設備封裝:14-SOIC 包裝:帶卷 (TR) |
| AD8657 | 制造商:AD 制造商全稱:Analog Devices 功能描述:18 V, Precision, Micropower CMOS RRIO Operational Amplifier |
| AD8657_11 | 制造商:AD 制造商全稱:Analog Devices 功能描述:18 V, Precision, Micropower CMOS RRIO Operational Amplifier |
| AD8657ACPZ-R7 | 功能描述:IC OPAMP R-R 18V 200KHZ 8LFCSP RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標準包裝:2,500 系列:- 放大器類型:通用 電路數:1 輸出類型:滿擺幅 轉換速率:0.11 V/µs 增益帶寬積:350kHz -3db帶寬:- 電流 - 輸入偏壓:4nA 電壓 - 輸入偏移:20µV 電流 - 電源:260µA 電流 - 輸出 / 通道:20mA 電壓 - 電源，單路/雙路(±):2.7 V ~ 36 V，±1.35 V ~ 18 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-SOIC（0.154"，3.90mm 寬） 供應商設備封裝:8-SO 包裝:帶卷 (TR) |
| AD8657ACPZ-RL | 功能描述:IC OPAMP R-R 18V 200KHZ 8LFCSP RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標準包裝:2,500 系列:- 放大器類型:通用 電路數:1 輸出類型:滿擺幅 轉換速率:0.11 V/µs 增益帶寬積:350kHz -3db帶寬:- 電流 - 輸入偏壓:4nA 電壓 - 輸入偏移:20µV 電流 - 電源:260µA 電流 - 輸出 / 通道:20mA 電壓 - 電源，單路/雙路(±):2.7 V ~ 36 V，±1.35 V ~ 18 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-SOIC（0.154"，3.90mm 寬） 供應商設備封裝:8-SO 包裝:帶卷 (TR) |
發布緊急采購，3分鐘左右您將得到回復。