參數(shù)資料
型號: LM614MN
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 運(yùn)動控制電子
英文描述: Quad Operational Amplifier and Adjustable Reference
中文描述: QUAD OP-AMP, 7000 uV OFFSET-MAX, 0.52 MHz BAND WIDTH, PDIP16
封裝: PLASTIC, DIP-16
文件頁數(shù): 12/15頁
文件大?。?/td> 402K
代理商: LM614MN
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
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PDF描述
LM614 Quad Operational Amplifier and Adjustable Reference
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LM614N WAF 制造商:Texas Instruments 功能描述:
LM614WM 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Quad Operational Amplifier and Adjustable Reference
LM614WN 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Voltage-Feedback Operational Amplifier
LM615 制造商:Texas Instruments 功能描述:
LM6152 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Dual and Quad High Speed/Low Power 75 MHz GBW Rail-to-Rail I/O Operational Amplifiers