參數(shù)資料
型號: LMV921M7X
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 運算放大器
英文描述: 1.8V, 1MHz, Low Power Operational Amplifiers with Rail-To-Rail Input and Output
中文描述: OP-AMP, 6000 uV OFFSET-MAX, 1 MHz BAND WIDTH, PDSO5
封裝: SC-70, 5 PIN
文件頁數(shù): 18/27頁
文件大小: 736K
代理商: LMV921M7X
Typical Applications
(Continued)
2.0 Instrumentation Amplifier with Rail-To-Rail Input and
Output
Using three of the LMV924 Amplifiers, an instrumentation
amplifier with rail-to-rail inputs and outputs can be made.
Some manufacturers use a precision voltage divider array of
5 resistors to divide the common mode voltage to get a
rail-to-rail input range. The problem with this method is that it
also divides the signal, so in order to get unity gain, the am-
plifier must be run at high loop gains. This raises the noise
and drift by the internal gain factor and lowers the input im-
pedance. Any mismatch in these precision resistors reduces
the CMRR as well. Using the LMV924 eliminates all of these
problems.
In this example, amplifiers A and B act as buffers to the dif-
ferential stage. These buffers assure that the input imped-
ance is very high and require no precision matched resistors
in the input stage. They also assure that the difference amp
is driven from a voltage source. This is necessary to main-
tain the CMRR set by the matching R
1
-R
2
with R
3
-R
4
.
The gain is set by the ratio of R
2
/R
1
and R
3
should equal R
1
and R
4
equal R
2
.
With both rail-to-rail input and output ranges, the input and
output are only limited by the supply voltages. Remember
that even with rail-to-rail outputs, the output can not swing
past the supplies so the combined common mode voltages
plus the signal should not be greater that the supplies or lim-
iting will occur. For additional applications, see National
Semiconductor application notes AN–29, AN–31, AN–71,
and AN–127.
DS100979-G4
FIGURE 7. Rail-to-rail instrumentation amplifier
L
www.national.com
18
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相關代理商/技術參數(shù)
參數(shù)描述
LMV922 制造商:NSC 制造商全稱:National Semiconductor 功能描述:1.8V, 1MHz, Low Power Operational Amplifiers with Rail-To-Rail Input and Output
LMV922A WAF 制造商:Texas Instruments 功能描述:
LMV922M 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:OC White Company 功能描述:OP Amp Dual GP R-R I/O 5V 8-Pin SOIC N Rail
LMV922MM 制造商:Texas Instruments 功能描述:
LMV922MMX 功能描述:IC OP AMP LO PWR RRIO 8-MSOP RoHS:否 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標準包裝:1,000 系列:- 放大器類型:電壓反饋 電路數(shù):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)