- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄373889 > AD648JR (ANALOG DEVICES INC) Dual Precision, Low Power BiFET Op Amp PDF資料下載
參數(shù)資料
| 型號： | AD648JR |
| 廠商： | ANALOG DEVICES INC |
| 元件分類： | 運動控制電子 |
| 英文描述： | Dual Precision, Low Power BiFET Op Amp |
| 中文描述： | DUAL OP-AMP, 3000 uV OFFSET-MAX, 1 MHz BAND WIDTH, PDSO8 |
| 封裝： | PLASTIC, SOIC-8 |
| 文件頁數(shù)： | 10/12頁 |
| 文件大?。?/td> | 335K |
| 代理商： | AD648JR |
AD648
REV. C
–10–
LOG RAT IO AMPLIFIE R
Log ratio amplifiers are useful for a variety of signal condition-
ing applications, such as linearizing exponential transducer out-
puts and compressing analog signals having a wide dynamic
range. T he AD648’s picoamp level input current and low input
offset voltage make it a good choice for the front-end amplifier
of the log ratio circuit shown in Figure 30. T his circuit produces
an output voltage equal to the log base 10 of the ratio of the in-
put currents I
1
and I
2
. Resistive inputs R1 and R2 are provided
for voltage inputs.
Input currents I
1
and I
2
set the collector currents of Q1 and Q2,
a matched pair of logging transistors. Voltages at points A and B
are developed according to the following familiar diode equation:
V
BE
=
(
kT/q
)
ln
(
I
C
I
ES
)
In this equation, k is Boltzmann’s constant, T is absolute tem-
perature, q is an electron charge, and I
ES
is the reverse satura-
tion current of the logging transistors. T he difference of these
two voltages is taken by the subtractor section and scaled by a
factor of approximately 16 by resistors R9, R10 and R8. T em-
perature compensation is provided by resistors R8 and R15,
which have a positive 3500 ppm/
°
C temperature coefficient.
T he transfer function for the output voltage is:
V
OUT
=
1
V log
10
(I
2
/I
1
)
Frequency compensation is provided by R11, R12, C1, and C2.
Small signal bandwidth is approximately 300 kHz at input cur-
rents above 100
μ
A and will proportionally decrease with lower
signal levels. D1, D2, R13, and R14 compensate for the effects
of the two logging transistors’ ohmic emitter resistance.
T o trim this circuit, set the two input currents to 10
μ
A and ad-
just V
OUT
to zero by adjusting the potentiometer on A3. T hen
set I
2
to 1
μ
A and adjust the scale factor such that the output
voltage is 1 V by trimming potentiometer R10. Offset adjust-
ment for A1 and A2 is provided to increase the accuracy of the
voltage inputs.
T his circuit ensures a 1% log conformance error over an input
current range of 300 pA to l mA, with low level accuracy limited
by the AD648’s input current. T he low level input voltage accu-
racy of this circuit is limited by the input offset voltage and drift
of the AD648.
Figure 30. Precision Log Ratio Amplifier
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| AD648JR-REEL | CAPACITOR 0805 X7R 10NF 100V 10%CAPACITOR 0805 X7R 10NF 100V 10%; CAPACITANCE:10NF; VOLTAGE RATING, DC:100V; CAPACITOR DIELECTRIC TYPE:CERAMIC MULTI-LAYER; SERIES:B37941; TOLERANCE, :10%; TOLERANCE, -:10%; TEMP, OP. MAX:125(DEGREE RoHS Compliant: Yes |
| AD648JR-REEL7 | Dual Precision, Low Power BiFET Op Amp |
| AD648KR-REEL | Dual Precision, Low Power BiFET Op Amp |
| AD648KR-REEL7 | Dual Precision, Low Power BiFET Op Amp |
| AD648 | Dual Precision, Low Power BiFET Op Amp |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| AD648JR-REEL | 制造商:Analog Devices 功能描述:OP Amp Dual GP ±18V 8-Pin SOIC N T/R |
| AD648JR-REEL7 | 制造商:Analog Devices 功能描述:OP Amp Dual GP ±18V 8-Pin SOIC N T/R |
| AD648JRZ | 功能描述:IC OPAMP BIFET 1MHZ DUAL 8SOIC RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 產(chǎn)品培訓(xùn)模塊:Differential Circuit Design Techniques for Communication Applications 標(biāo)準(zhǔn)包裝:1 系列:- 放大器類型:RF/IF 差分 電路數(shù):1 輸出類型:差分 轉(zhuǎn)換速率:9800 V/µs 增益帶寬積:- -3db帶寬:2.9GHz 電流 - 輸入偏壓:3µA 電壓 - 輸入偏移:- 電流 - 電源:40mA 電流 - 輸出 / 通道:- 電壓 - 電源，單路/雙路(±):3 V ~ 3.6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:16-VQFN 裸露焊盤，CSP 供應(yīng)商設(shè)備封裝:16-LFCSP-VQ 包裝:剪切帶 (CT) 產(chǎn)品目錄頁面:551 (CN2011-ZH PDF) 其它名稱:ADL5561ACPZ-R7CT |
| AD648JRZ | 制造商:Analog Devices 功能描述:Operational Amplifier (Op-Amp) IC |
| AD648JRZ-REEL | 功能描述:IC OPAMP BIFET 1MHZ DUAL 8SOIC RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:50 系列:- 放大器類型:通用 電路數(shù):2 輸出類型:滿擺幅 轉(zhuǎn)換速率:1.8 V/µs 增益帶寬積:6.5MHz -3db帶寬:4.5MHz 電流 - 輸入偏壓:5nA 電壓 - 輸入偏移:100µV 電流 - 電源:65µA 電流 - 輸出 / 通道:35mA 電壓 - 電源，單路/雙路(±):1.8 V ~ 5.25 V，±0.9 V ~ 2.625 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:10-TFSOP，10-MSOP（0.118"，3.00mm 寬） 供應(yīng)商設(shè)備封裝:10-MSOP 包裝:管件 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。