參數(shù)資料
型號(hào): op495
廠商: Analog Devices, Inc.
英文描述: Rail to Rail Quad OP AMP(滿幅度四運(yùn)算放大器)
中文描述: 軌至軌四路運(yùn)算放大器(滿幅度四運(yùn)算放大器)
文件頁(yè)數(shù): 9/12頁(yè)
文件大?。?/td> 337K
代理商: OP495
OP295/OP495
REV. B
–9–
common-mode rejection performance and minimize drift. T his
instrumentation amplifier can operate from a supply voltage as
low as 3 volts.
A Single Supply RT D T hermometer Amplifier
T his RT D amplifier takes advantage of the rail-to-rail swing of
the OP295/OP495 to achieve a high bridge voltage in spite of a
low 5 V supply. T he OP295/OP495 amplifier servos a constant
200
μ
A current to the bridge. T he return current drops across
the parallel resistors 6.19 k
and the 2.55 M
, developing a
voltage that is servoed to 1.235 V, which is established by the
AD589 bandgap reference. T he 3-wire RT D provides an equal
line resistance drop in both 100
legs of the bridge, thus im-
proving the accuracy.
T he AMP04 amplifies the differential bridge signal and converts
it to a single-ended output. T he gain is set by the series resis-
tance of the 332
resistor plus the 50
potentiometer. T he
gain scales the output to produce a 4.5 V full scale. T he
0.22
μ
F capacitor to the output provides a 7 Hz low-pass filter
to keep noise at a minimum.
3
7
1
8
6
5
4
2
AMP04
0.22
μ
F
332
50
26.7k
0.5%
100
0.5%
100
RTD
2.55M
1%
6.19k
1%
AD589
1.235
37.4k
+5V
200
10-TURNS
ZERO ADJ
26.7k
0.5%
V
O
4.5V = 450
°
C
0V = 0
°
C
+5V
1
2
3
1/2
OP295/
OP495
Figure 6. Low Power RTD Amplifier
A Cold Junction Compensated, Battery Powered
T hermocouple Amplifier
T he OP295/OP495’s 150
μ
A quiescent current per amplifier
consumption makes it useful for battery powered temperature
measuring instruments. T he K -type thermocouple terminates
into an isothermal block where the terminated junctions’ ambi-
ent temperatures can be continuously monitored and corrected
by summing an equal but opposite thermal EMF to the ampli-
fier, thereby canceling the error introduced by the cold junctions.
V
O
0V = 0
°
C
5V = 500
°
C
4.99k
1%
1.33M
20k
SCALE
ADJUST
9V
24.3k
1%
24.9k
7.15k
1%
1.235V
AD589
24.9k
1%
500
10-TURN
2.1k
1%
475
1%
1.5M
1%
1N914
ISOTHERMAL
BLOCK
COLD
JUNCTIONS
CR
AL
CHROMEL
K-TYPE
THERMOCOUPLE
40.7
μ
V/
°
C
ZERO
ADJUST
8
1
4
2
3
ALUMEL
OP295/
OP495
Figure 7. Battery Powered, Cold-J unction Compensated
Thermocouple Amplifier
T o calibrate, immerse the thermocouple measuring junction in a
0
°
C ice bath, adjust the 500
Zero Adjust pot to zero volts out.
T hen immerse the thermocouple in a 250
°
C temperature bath
or oven and adjust the Scale Adjust pot for an output voltage of
2.50 V, which is equivalent to 250
°
C. Within this temperature
range, the K -type thermocouple is quite accurate and produces
a fairly linear transfer characteristic. Accuracy of
±
3
°
C is achiev-
able without linearization.
Even if the battery voltage is allowed to decay to as low as 7 volts,
the rail-to-rail swing allows temperature measurements to
700
°
C. However, linearization may be necessary for tempera-
tures above 250
°
C where the thermocouple becomes rather
nonlinear. T he circuit draws just under 500
μ
A supply current
from a 9 V battery.
A 5 V Only, 12-Bit DAC T hat Swings 0 V to 4.095 V
Figure 8 shows a complete voltage output DAC with wide out-
put voltage swing operating off a single +5 V supply. T he serial
input 12-bit D/A converter is configured as a voltage output
device with the 1.235 V reference feeding the current output pin
(I
OUT
) of the DAC. T he V
REF
which is normally the input now
becomes the output.
T he output voltage from the DAC is the binary weighted volt-
age of the reference, which is gained up by the output amplifier
such that the DAC has a 1 mV per bit transfer function.
+5V
R2
41.2k
R3
5k
R4
100k
V
DD
R
FB
V
REF
SRI
CLK
GND
I
OUT
DAC8043
3
4
7
6
5
1
2
8
+5V
DIGITAL
CONTROL
+5V
AD589
R1
17.8k
+1.23V
LD
V
O
=
1
(4.096V)
D
4096
TOTAL POWER DISSIPATION = 1.6mW
8
4
2
3
OP295/
OP495
Figure 8. A 5 Volt 12-Bit DAC with 0 V to +4.095 Output
Swing
4–20 mA Current Loop T ransmitter
Figure 9 shows a self powered 4–20 mA current loop transmit-
ter. T he entire circuit floats up from the single supply (12 V to
36 V) return. T he supply current carries the signal within the 4
to 20 mA range. T hus the 4 mA establishes the baseline
8
1
2
3
220pF
220
REF02
GND
6
2
4
100
2N1711
100k
1%
HP
5082-2800
100
1%
V
0 + 3V
100k
10-TURN
1.21M
1%
NULL ADJ
SPAN ADJ
182k
1%
10k
10-TURN
5V
+12V
TO
+36V
R
L
100
4–20mA
4
1/2
OP295/
OP495
Figure 9. 4–20 mA Current Loop Transmitter
相關(guān)PDF資料
PDF描述
OP296 Micropower, Rail-to-Rail Input and Output Operational Amplifiers(微功耗,滿幅度輸入輸出雙運(yùn)放)
OP496 Micropower, Rail-to-Rail Input and Output Operational Amplifiers(微功耗,滿幅度輸入輸出四運(yùn)放)
op297 Dual Low Bias Current Precision Operational Amplifier(低偏置電流精密雙運(yùn)放)
OP37EZ Low Noise, Precision, High Speed Operational Amplifier
OP37AZ Low Noise, Precision, High Speed Operational Amplifier
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
OP495AY/883 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Voltage-Feedback Operational Amplifier
OP495AZ/883 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Voltage-Feedback Operational Amplifier
OP495GBC 制造商:AD 制造商全稱:Analog Devices 功能描述:DUAL/QUAD RAIL-TO-RAIL OPERATIONAL AMPLIFIERS
OP495GP 制造商:Analog Devices 功能描述:OP Amp Quad GP R-R O/P 制造商:Rochester Electronics LLC 功能描述:QUAD RAIL-TO-RAIL AMP IC - Bulk 制造商:Analog Devices 功能描述:AMPLIFIER IC NUMBER OF CIRCUITS:1
OP495GPZ 功能描述:IC OPAMP GP R-R 85KHZ QUAD 14DIP RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 放大器類型:通用 電路數(shù):4 輸出類型:- 轉(zhuǎn)換速率:0.6 V/µs 增益帶寬積:1MHz -3db帶寬:- 電流 - 輸入偏壓:45nA 電壓 - 輸入偏移:2000µV 電流 - 電源:1.4mA 電流 - 輸出 / 通道:40mA 電壓 - 電源,單路/雙路(±):3 V ~ 32 V,±1.5 V ~ 16 V 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:14-TSSOP(0.173",4.40mm 寬) 供應(yīng)商設(shè)備封裝:14-TSSOP 包裝:帶卷 (TR) 其它名稱:LM324ADTBR2G-NDLM324ADTBR2GOSTR