參數(shù)資料
型號(hào)： OP491GSZ
廠商： Analog Devices Inc
文件頁(yè)數(shù)： 9/24頁(yè)
文件大?。?/td> 0K
描述： IC OPAMP GP R-R 3MHZ QUAD 14SOIC
標(biāo)準(zhǔn)包裝： 56
放大器類(lèi)型： 通用
電路數(shù)： 4
輸出類(lèi)型： 滿擺幅
轉(zhuǎn)換速率： 0.5 V/µs
增益帶寬積： 3MHz
電流 - 輸入偏壓： 30nA
電壓 - 輸入偏移： 80µV
電流 - 電源： 260µA
電流 - 輸出 / 通道： 16mA
電壓 - 電源，單路/雙路(±)： 2.7 V ~ 12 V，±1.35 V ~ 6 V
工作溫度： -40°C ~ 125°C
安裝類(lèi)型： 表面貼裝
封裝/外殼： 14-SOIC（0.154"，3.90mm 寬）
供應(yīng)商設(shè)備封裝： 14-SOIC
包裝： 管件
產(chǎn)品目錄頁(yè)面： 774 (CN2011-ZH PDF)
OP191/OP291/OP491
Rev. E | Page 17 of 24
THEORY OF OPERATION
The OP191/OP291/OP491 are single-supply, micropower
amplifiers featuring rail-to-rail inputs and outputs. To achieve
wide input and output ranges, these amplifiers employ unique
input and output stages. In Figure 61 , the input stage comprises
two differential pairs, a PNP pair and an NPN pair. These two
stages do not work in parallel. Instead, only one stage is on for
any given input signal level. The PNP stage (Transistor Q1 and
Transistor Q2) is required to ensure that the amplifier remains
in the linear region when the input voltage approaches and
reaches the negative rail. On the other hand, the NPN stage
(Transistor Q5 and Transistor Q6) is needed for input voltages
up to and including the positive rail.
For the majority of the input common-mode range, the PNP
stage is active, as is shown in Figure 12. Notice that the bias
current switches direction at approximately 1.2 V to 1.3 V
below the positive rail. At voltages below this, the bias current
flows out of the OP291, indicating a PNP input stage. Above
this voltage, however, the bias current enters the device,
revealing the NPN stage. The actual mechanism within the
amplifier for switching between the input stages comprises
Transistor Q3, Transistor Q4, and Transistor Q7. As the input
common-mode voltage increases, the emitters of Q1 and Q2
follow that voltage plus a diode drop. Eventually, the emitters
of Q1 and Q2 are high enough to turn on Q3, which diverts the
8 μA of tail current away from the PNP input stage, turning it
off. Instead, the current is mirrored through Q4 and Q7 to
activate the NPN input stage.
Notice that the input stage includes 5 kΩ series resistors and
differential diodes, a common practice in bipolar amplifiers to
protect the input transistors from large differential voltages.
These diodes turn on whenever the differential voltage exceeds
approximately 0.6 V. In this condition, current flows between
the input pins, limited only by the two 5 kΩ resistors. This
characteristic is important in circuits where the amplifier may
be operated open-loop, such as a comparator. Evaluate each
circuit carefully to make sure that the increase in current does
not affect the performance.
The output stage in OP191 devices uses a PNP and an NPN
transistor, as do most output stages; however, Q32 and Q33, the
output transistors, are actually connected with their collectors
to the output pin to achieve the rail-to-rail output swing. As the
output voltage approaches either the positive or negative rail,
these transistors begin to saturate. Thus, the final limit on
output voltage is the saturation voltage of these transistors,
which is about 50 mV. The output stage does have inherent gain
arising from the collectors and any external load impedance.
Because of this, the open-loop gain of the amplifier is
dependent on the load resistance.
Q1
8A
5k
Q3
5k
–IN
Q5 Q6
Q11
Q10
Q8
Q7
Q4
Q13
Q15
Q14
Q12
Q9
Q16
Q17
Q18
Q19
Q20
Q21
Q24
Q23
Q22
Q27
Q26
Q30
Q31
Q28
Q25
Q29
Q32
VOUT
Q33
10pF
+IN
Q2
0
02
94
-06
5
Figure 61. Simplified Schematic
相關(guān)PDF資料
PDF描述
PEC16SFCN CONN HEADER .100 SINGL STR 16POS
TSW-102-23-G-D CONN HEADER 4POS .100" DUAL GOLD
OP491GPZ IC OPAMP GP R-R 3MHZ QUAD 14DIP
AD626ARZ-REEL7 IC AMP DIFF LP 12MA 8SOIC
PEC32SFAN CONN HEADER .100 SINGL STR 32POS
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
OP491GSZ-REEL 功能描述:IC OPAMP GP R-R 3MHZ QUAD 14SOIC RoHS:是 類(lèi)別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:50 系列:- 放大器類(lèi)型:J-FET 電路數(shù):2 輸出類(lèi)型:- 轉(zhuǎn)換速率:13 V/µs 增益帶寬積:3MHz -3db帶寬:- 電流 - 輸入偏壓:65pA 電壓 - 輸入偏移:3000µV 電流 - 電源:1.4mA 電流 - 輸出 / 通道:- 電壓 - 電源，單路/雙路(±):7 V ~ 36 V，±3.5 V ~ 18 V 工作溫度:-40°C ~ 85°C 安裝類(lèi)型:通孔 封裝/外殼:8-DIP（0.300"，7.62mm） 供應(yīng)商設(shè)備封裝:8-PDIP 包裝:管件
OP491GSZ-REEL7 功能描述:IC OPAMP GP R-R 3MHZ QUAD 14SOIC RoHS:是 類(lèi)別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:50 系列:- 放大器類(lèi)型:J-FET 電路數(shù):2 輸出類(lèi)型:- 轉(zhuǎn)換速率:13 V/µs 增益帶寬積:3MHz -3db帶寬:- 電流 - 輸入偏壓:65pA 電壓 - 輸入偏移:3000µV 電流 - 電源:1.4mA 電流 - 輸出 / 通道:- 電壓 - 電源，單路/雙路(±):7 V ~ 36 V，±3.5 V ~ 18 V 工作溫度:-40°C ~ 85°C 安裝類(lèi)型:通孔 封裝/外殼:8-DIP（0.300"，7.62mm） 供應(yīng)商設(shè)備封裝:8-PDIP 包裝:管件
OP491HRU 制造商:AD 制造商全稱:Analog Devices 功能描述:Micropower Single-Supply Rail-to-Rail Input/Output Op Amps
OP492 制造商:AD 制造商全稱:Analog Devices 功能描述:DUAL/QUAD SINGLE SUPPLY OPERATIONAL AMPLIFIER
OP-492 制造商:AD 制造商全稱:Analog Devices 功能描述:DUAL/QUAD SINGLE SUPPLY OPERATIONAL AMPLIFIER
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*