參數(shù)資料
型號(hào): LM614CWMX
英文描述: Voltage-Feedback Operational Amplifier
中文描述: 電壓反饋運(yùn)算放大器
文件頁(yè)數(shù): 12/15頁(yè)
文件大?。?/td> 402K
代理商: LM614CWMX
Typical Applications
(Continued)
ANALOG TO DIGITAL CONVERTER BUFFER
The high capacitive load driving ability, rail-to-rail input and
output range with the excellent CMR of 82 dB, make the
LM6142/44 a good choice for buffering the inputs of A to D
converters.
3 OPAMP INSTRUMENTATION AMP WITH
RAIL-TO-RAIL INPUT AND OUTPUT
Using the LM6144, a 3 opamp instrumentation amplifier with
rail-to-rail inputs and rail to rail output can be made. These
features make these instrumentation amplifiers ideal for
single supply systems.
Some manufacturers use a precision voltage divider array of
5 resistors to divide the common-mode voltage to get an in-
put range of rail-to-rail or greater. The problem with this
method is that it also divides the signal, so to even get unity
gain, the amplifier must be run at high closed loop gains.
This raises the noise and drift by the internal gain factor and
lowers the input impedance. Any mismatch in these preci-
sion resistors reduces the CMR as well. Using the LM6144,
all of these problems are eliminated.
In this example, amplifiers A and B act as buffers to the dif-
ferential stage (Figure 6). These buffers assure that the input
impedance is over 100 M
and they eliminate the require-
ment for precision matched resistors in the input stage. They
also assure that the difference amp is driven from a voltage
source. This is necessary to maintain the CMR set by the
matching of R1–R2 with R3–R4.
The gain is set by the ratio of R2/R1 and R3 should equal R1
and R4 equal R2. Making R4 slightly smaller than R2 and
adding a trim pot equal to twice the difference between R2
and R4 will allow the CMR to be adjusted for optimum.
With both rail to rail input and output ranges, the inputs and
outputs are only limited by the supply voltages. Remember
that even with rail-to-rail output, the output can not swing
past the supplies so the combined common mode voltage
plus the signal should not be greater than the supplies or lim-
iting will occur.
SPICE MACROMODEL
A SPICE macromodel of this and many other National Semi-
conductor opamps is available at no charge from the NSC
Customer Response Group at 800-272-9959.
DS012057-13
FIGURE 6.
L
www.national.com
12
相關(guān)PDF資料
PDF描述
LM614IJ Voltage-Feedback Operational Amplifier
LM614IN Voltage-Feedback Operational Amplifier
LM614IWM IC-SM-QUAD AMP/ADJ REF
LM6142AIMX Voltage-Feedback Operational Amplifier
LM6142BIMX Voltage-Feedback Operational Amplifier
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LM614CWMX/NOPB 制造商:Texas Instruments 功能描述:OP Amp Quad GP 32V 16-Pin SOIC W T/R
LM614IJ 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Voltage-Feedback Operational Amplifier
LM614IN 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Voltage-Feedback Operational Amplifier
LM614IWM 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
LM614IWM/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