參數(shù)資料
型號(hào): LMV841MGX
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 運(yùn)動(dòng)控制電子
英文描述: CMOS Input, RRIO, Wide Supply Range Operational Amplifier
中文描述: OP-AMP, 800 uV OFFSET-MAX, 4.5 MHz BAND WIDTH, PDSO5
封裝: SC-70, 5 PIN
文件頁(yè)數(shù): 12/16頁(yè)
文件大?。?/td> 899K
代理商: LMV841MGX
To determine if the noise is acceptable for the application, use
the following formula for resistor noise :
where:
e
th
= Thermal noise voltage (Vrms)
k = Boltzmann constant (1.38 x 10–23 J/K)
T = Absolute temperature (K)
R = Resistance (
Ω)
B = Noise bandwidth (Hz), fmax - fmin
Given in an example with a resistor of 1MOhm at 25°C (298
K) over a frequency range of 100 kHz:
To keep the noise of the application low it might be necessary
to decrease the resistors to 100k, which will decrease the
noise to –97.8 dBV (12.8 uV).
The op amp's input-referred noise of 20 nV/
equivalent to the noise of a 24 k
Ω
resistor.
at 1 kHz is
ACTIVE FILTER
The rail-to-rail input and output of the LMV841, and its wide
supply voltage range makes this amplifier ideal to use in nu-
merous applications. One of the typical applications is an
active filter as shown in
Figure 3
. This example is a band-pass
filter, for which the pass band is widened. This is achieved by
cascading two band-pass filters, with slightly different centre
frequencies.
20168358
FIGURE 3. Active Filter
The centre frequency of the separate band-pass filters can be
calculated by:
In this example a filter was designed with its pass band at 10
kHz. The two separate band-pass filters are designed to have
a centre frequency of approximately 10% from the frequency
of the total filter:
C = 33 nF
R1 = 2 k
Ω
R2 = 6.2 k
Ω
R3 = 45
Ω
This will give for Filter A
And for filter B with C = 27 nF:
Bandwidth can be calculated by:
For filter A this will give
and for filter B:
The response of the two filters and the combined filter is
shown in
Figure 4
.
20168359
FIGURE 4. Active Filter Curve
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相關(guān)代理商/技術(shù)參數(shù)
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LMV841MGX/NOPB 功能描述:運(yùn)算放大器 - 運(yùn)放 RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比(最小值):63 dB 輸入補(bǔ)償電壓:1 mV 輸入偏流(最大值):10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel
LMV841QMG 制造商:TI 制造商全稱:Texas Instruments 功能描述:LMV841/LMV841Q/LMV842/LMV842Q/LMV844/LMV844Q CMOS Input, RRIO, Wide Supply Range Operational Amplifiers
LMV841QMG/NOPB 功能描述:運(yùn)算放大器 - 運(yùn)放 RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比(最小值):63 dB 輸入補(bǔ)償電壓:1 mV 輸入偏流(最大值):10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel
LMV841QMGX 制造商:TI 制造商全稱:Texas Instruments 功能描述:LMV841/LMV841Q/LMV842/LMV842Q/LMV844/LMV844Q CMOS Input, RRIO, Wide Supply Range Operational Amplifiers
LMV841QMGX/NOPB 功能描述:運(yùn)算放大器 - 運(yùn)放 RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比(最小值):63 dB 輸入補(bǔ)償電壓:1 mV 輸入偏流(最大值):10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel