AD704TQ [ADI]
Quad Picoampere Input Current Bipolar Op Amp; 四Picoampere输入电流双极运算放大器
| 型号： | AD704TQ |
| 厂家： | 
ADI |
| 描述： | Quad Picoampere Input Current Bipolar Op Amp |
| 文件： | 总8页 (文件大小：400K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Quad Picoampere Input Current
Bipolar Op Amp
a
AD704
FEATURES
CONNECTION DIAGRAMS
High DC Precision
75 V max Offset Voltage
1 V/؇C max Offset Voltage Drift
150 pA max Input Bias Current
0.2 pA/؇C typical IB Drift
14-Pin Plastic DIP (N)
14-Pin Cerdip (Q) Packages
16-Pin SOIC
(R) Package
OUTPUT
–IN
14
13
12
11
10
9
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
OUTPUT
–IN
OUTPUT
–IN
1
2
3
4
5
6
7
8
OUTPUT
–IN
1
4
1
4
Low Noise
0.5 V p-p typical Noise, 0.1 Hz to 10 Hz
Low Power
600 A max Supply Current per Amplifier
Chips & MIL-STD-883B Processing Available
Available in Tape and Reel in Accordance
with EIA-481A Standard
+
+
IN
+
IN
+
IN
IN
AD704
AD704
+V
S
+V
S
–V
+
–V
S
S
(TOP VIEW)
(TOP VIEW)
+
IN
IN
+
+
IN
IN
–IN
OUTPUT
NC
2
3
–IN
–IN
–IN
2
3
OUTPUT
NC
OUTPUT
8
OUTPUT
Single Version: AD705, Dual Version: AD706
PRIMARY APPLICATIONS
Industrial/Process Controls
Weigh Scales
ECG/EKG Instrumentation
Low Frequency Active Filters
NC = NO CONNECT
20-Terminal LCC
(E) Package
1
3
2
20 19
PRODUCT DESCRIPTION
4
+IN1
+IN4
NC
18
The AD704 is a quad, low power bipolar op amp that has the
low input bias current of a BiFET amplifier but which offers a
significantly lower IB drift over temperature. It utilizes Super-
beta bipolar input transistors to achieve picoampere input bias
current levels (similar to FET input amplifiers at room tempera-
ture), while its IB typically only increases by 5× at +125°C
(unlike a BiFET amp, for which IB doubles every 10°C resulting
in a 1000× increase at +125°C). Furthermore the AD704
achieves 75 µV offset voltage and low noise characteristics of a
precision bipolar input op amp.
NC 5
17
16
AMP 1
AMP 4
+V
–V
S
6
7
S
AD704
AMP 2
AMP 3
NC
15 NC
+IN2 8
14 +IN3
9
11
13
10
12
NC = NO CONNECT
100
Since it has only 1/20 the input bias current of an AD OP07, the
AD704 does not require the commonly used “balancing”
resistor. Furthermore, the current noise is 1/5 that of the
AD OP07 which makes the AD704 usable with much higher
source impedances. At 1/6 the supply current (per amplifier) of
the AD OP07, the AD704 is better suited for today’s higher
density circuit boards and battery powered applications.
10
TYPICAL JFET AMP
1
The AD704 is an excellent choice for use in low frequency
active filters in 12- and 14-bit data acquisition systems, in
precision instrumentation, and as a high quality integrator. The
AD704 is internally compensated for unity gain and is available
in five performance grades. The AD704J and AD704K are rated
over the commercial temperature range of 0°C to +70°C. The
AD704A and AD704B are rated over the industrial temperature
of –40°C to +85°C. The AD704T is rated over the military
temperature range of –55°C to +125°C and is available
processed to MIL-STD-883B, Rev. C.
0.1
AD704T
0.01
–55
+25
+125
TEMPERATURE – °C
Figure 1. Input Bias Current Over Temperature
REV. A
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
AD704–SPECIFICATIONS
(@ TA = +25؇C, VCM = 0 V, and ؎15 V dc, unless otherwise noted)
Model
AD704J/A
AD704K/B
AD704T
Conditions
Min Typ Max Min Typ Max Min Typ Max Units
INPUT OFFSET VOLTAGE
Initial Offset
Offset
vs. Temp, Average TC
vs. Supply (PSRR)
50
150
250
1.5
30
50
0.2
132
126
0.3
75
150
1.0
30
80
100
150
1.0
µV
µV
µV/°C
dB
dB
T
MIN–TMAX
100
0.2
132
126
0.3
VS = ±2 to ±18 V
VS = ±2.5 to ±18 V 100
100
112
108
112
108
132
126
0.3
T
MIN–TMAX
Long Term Stability
µV/month
INPUT BIAS CURRENT1
VCM = 0 V
VCM = ±13.5 V
100
0.3
270
300
80
150
200
80
200
250
pA
pA
pA/°C
pA
pA
vs. Temp, Average TC
TMIN–TMAX
TMIN–TMAX
0.2
1.0
VCM = 0 V
VCM = ±13.5 V
300
400
200
300
600
700
INPUT OFFSET CURRENT
V
CM = 0 V
80
250
300
30
100
150
50
150
200
pA
pA
VCM = ±13.5 V
vs. Temp, Average TC
0.6
100
100
0.4
80
80
0.4
80
100
pA/°C
pA
pA
T
MIN–TMAX
VCM = 0 V
VCM = ±13.5 V
300
400
200
300
400
500
TMIN–TMAX
MATCHING CHARACTERISTICS
Offset Voltage
250
400
500
600
130
200
300
400
150
250
400
600
µV
µV
pA
pA
dB
dB
dB
dB
T
MIN–TMAX
Input Bias Current2
Common-Mode Rejection3
Power Supply Rejection4
Crosstalk5
TMIN–TMAX
TMIN–TMAX
94
94
94
94
110
104
110
106
104
104
110
106
T
MIN–TMAX
f = 10 Hz
RLOAD = 2 kΩ
150
150
150
dB
FREQUENCY RESPONSE
UNITY GAIN
Crossover Frequency
Slew Rate, Unity Gain
Slew Rate
0.8
0.15
0.1
0.8
0.15
0.1
0.8
0.15
0.1
MHz
V/µs
V/µs
G = –1
TMIN–TMAX
INPUT IMPEDANCE
Differential
Common-Mode
40ʈ2
300ʈ2
40ʈ2
300ʈ2
40ʈ2
300ʈ2
MΩʈpF
GΩʈpF
INPUT VOLTAGE RANGE
Common-Mode Voltage
±13.5 ±14
±13.5 ±14
±13.5 ±14
V
Common-Mode Rejection Ratio
VCM = ±13.5 V
TMIN–TMAX
100
98
132
128
114
108
132
128
110
108
132
128
dB
dB
INPUT CURRENT NOISE
INPUT VOLTAGE NOISE
0.1 to 10 Hz
f = 10 Hz
3
50
3
50
3
50
pA p-p
fA/√Hz
0.1 to 10 Hz
f = 10 Hz
f = 1 kHz
0.5
17
15
0.5
17
15
2.0
22
0.5
17
15
2.0
22
µV p-p
nV/√Hz
nV/√Hz
22
OPEN-LOOP GAIN
V
O = ±12 V
RLOAD = 10 kΩ
MIN–TMAX
200
150
2000
1500
400
300
2000
1500
400
300
2000
1500
V/mV
V/mV
T
VO = ±10 V
RLOAD = 2 kΩ
TMIN–TMAX
200
150
1000
1000
300
200
1000
1000
200
100
1000
1000
V/mV
V/mV
–2–
REV. A
AD704
Model
AD704J/A
AD704K/B
AD704T
Conditions
Min Typ Max Min Typ Max Min Typ Max Units
OUTPUT CHARACTERISTICS
Voltage Swing
R
LOAD = 10 kΩ
TMIN–TMAX
Short Circuit
±13 ±14
±15
± 13 ±14
±15
±13 ±14
±15
V
mA
Current
CAPACITIVE LOAD
Drive Capability
Gain = + 1
10,000
10,000
10,000
pF
POWER SUPPLY
Rated Performance
Operating Range
Quiescent Current
±15
±15
±15
V
V
mA
mA
±2.0
±18
2.4
2.6
±2.0
±18
2.4
2.6
±2.0
±18
2.4
2.6
1.5
1.6
1.5
1.6
1.5
1.6
TMIN–TMAX
TRANSISTOR COUNT
NOTES
# of Transistors
180
180
180
1Bias current specifications are guaranteed maximum at either input.
2Input bias current match is the maximum difference between corresponding inputs of all four amplifiers.
3CMRR match is the difference of ∆VOS/∆VCM between any two amplifiers, expressed in dB.
4PSRR match is the difference between ∆VOS/∆VSUPPLY for any two amplifiers, expressed in dB.
5See Figure 2a for test circuit.
All min and max specifications are guaranteed.
Specifications subject to change without notice.
ABSOLUTE MAXIMUM RATINGS1
METALIZATION PHOTOGRAPH
Dimensions shown in inches and (mm).
Contact factory for latest dimensions.
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±18 V
Internal Power Dissipation (+25°C) . . . . . . . . . . . See Note 2
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±VS
Differential Input Voltage3 . . . . . . . . . . . . . . . . . . . . . . . ±0.7 V
Output Short Circuit Duration (Single Input) . . . . . Indefinite
Storage Temperature Range
(Q) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C
(N, R) . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to +125°C
Operating Temperature Range
AD704J/K . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C
AD704A/B . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C
AD704T . . . . . . . . . . . . . . . . . . . . . . . . . . –55°C to +125°C
Lead Temperature Range (Soldering 10 seconds) . . . . +300°C
NOTES
1Stresses above those listed under “Absolute Maximum Ratings” may cause
permanent damage to the device. This is a stress rating only and functional
operation of the device at these or any other conditions above those indicated in
the operational section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
2Specification is for device in free air:
14-Pin Plastic Package: θJA = 150°C/Watt
14-Pin Cerdip Package: θJA = 110°C/Watt
–80
16-Pin SOIC Package: θJA = 100°C/Watt
20-Terminal LCC Package: θJA = 150°C/Watt
AMP4
3The input pins of this amplifier are protected by back-to-back diodes. If the
differential voltage exceeds ±0.7 volts, external series protection resistors should
be added to limit the input current to less than 25 mA.
–100
AMP2
AMP3
Ω
9k
–120
Ω
1k
OUTPUT
AD704
PIN 4
1/4
AD704
–140
–160
+V
S
0.1 µF
COM
0.1 µF
–V
1µF
1µF
INPUT
SIGNAL
*
Ω
2.5k
Ω
1k
S
AD704
PIN 11
10
100
1k
10k
100k
FREQUENCY – Hz
ALL 4 AMPLIFIERS ARE CONNECTED AS SHOWN
THE SIGNAL INPUT (SUCH THAT THE AMPLIFIER'S OUTPUT IS AT MAX
AMPLITUDE WITHOUT CLIPPING OR SLEW LIMITING) IS APPLIED TO ONE
AMPLIFIER AT A TIME. THE OUTPUTS OF THE OTHER THREE AMPLIFIERS ARE
THEN MEASURED FOR CROSSTALK.
*
Figure 2b. Crosstalk vs. Frequency
Figure 2a. Crosstalk Test Circuit
–3–
REV. A
AD704–Typical Characteristics(@ +25؇C, VS = ؎15 V, unless otherwise noted)
ORDERING GUIDE
Model
Temperature Range Package Option*
AD704JN
AD704JR
0°C to +70°C
0°C to +70°C
N-14
R-16
AD704JR-/REEL 0°C to +70°C
Tape and Reel
N-14
N-14
Q-14
R-16
AD704KN
AD704AN
AD704AQ
AD704AR
0°C to +70°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
AD704AR-REEL –40°C to +85°C
Tape and Reel
Q-14
E-20A
Q-14
AD704BQ
–40°C to +85°C
–55°C to +125°C
–55°C to +125°C
–55°C to +125°C
AD704SE/883B
AD704TQ
AD704TQ/883B
Q-14
Chips are also available.
*E = Leadless Ceramic Chip Carrier; N = Plastic DIP; Q = Cerdip;
R = Small Outline (SOIC).
50
40
50
50
40
40
30
20
10
30
20
10
0
30
20
10
0
0
–40
INPUT OFFSET VOLTAGE – µV
+80
–80
0
+40
–80
INPUT BIAS CURRENT – pA
+160
–120
–60
0
+60
+120
–160
0
+80
INPUT OFFSET CURRENT – pA
Figure 3. Typical Distribution of
Input Offset Voltage
Figure 4. Typical Distribution of
Input Bias Current
Figure 5. Typical Distribution of
Input Offset Current
100
35
+V
S
SOURCE RESISTANCE
MAY BE EITHER BALANCED
OR UNBALANCED
–0.5
–1.0
–1.5
30
25
10
1.0
0.1
20
15
+1.5
+1.0
+0.5
10
5
–V
S
0
10k
100k
1M
100M
1k
1k
10k
100k
1M
10M
0
5
10
15
20
FREQUENCY – Hz
SOURCE RESISTANCE – Ω
SUPPLY VOLTAGE – Volts
Figure 6. Input Common-Mode
Voltage Range vs. Supply Voltage
Figure 7. Large Signal Frequency
Response
Figure 8. Offset Voltage Drift vs.
Source Resistance
–4–
REV. A
AD704
120
50
40
30
20
4
3
2
1
0
100
80
POSITIVE I
B
60
40
20
0
NEGATIVE I
B
10
0
10
COMMON MODE VOLTAGE – Volts
–15
–10
–5
0
5
15
–0.8
–0.4
0
+0.4
+0.8
0
1
2
3
4
5
INPUT OFFSET VOLTAGE DRIFT – µV/°C
WARM-UP TIME – Minutes
Figure 9. Typical Distribution of
Offset Voltage Drift
Figure 11. Input Bias Current vs.
Common-Mode Voltage
Figure 10. Change in Input Off-
set Voltage vs. Warm-Up Time
1000
100
1000
100
100Ω
10kΩ
10
10
20MΩ
VOUT
1
1
100
10
FREQUENCY – Hz
1
10
100
1000
1
1000
FREQUENCY – Hz
Figure 12. Input Noise Voltage
Spectral Density
Figure 14. 0.1 Hz to 10 Hz Noise
Voltage
Figure 13. Input Noise Current
Spectral Density
+160
180
160
140
500
V
T
= ±15V
S
A
+140
+120
= +25°C
450
400
V
= ± 15V
S
+100
+80
120
100
+125°C
–PSR
+60
+40
80
60
40
20
+25°C
+PSR
350
300
+20
0
–55°C
0.1
1
10
100
1M
10k 100k
5
20
1k
0
10
15
0.1
10
1
100
1M
1k
10k 100k
FREQUENCY – Hz
SUPPLY VOLTAGE – ±Volts
FREQUENCY – Hz
Figure 16. Common-Mode
Rejection vs. Frequency
Figure 17. Power Supply Rejection
vs. Frequency
Figure 15. Quiescent Supply
Current vs. Supply Voltage (per
Amplifier)
REV. A
–5–
AD704
10M
140
120
100
80
0
+V
S
R = 10kΩ
L
30
60
–0.5
–1.0
–1.5
–55 C
+25 C
PHASE
90
120
150
180
60
1M
+125 C
40
+1.5
+1.0
GAIN
20
0
+0.5
–V
S
–20
100k
1
0.01 0.1
1
10 100
10k 100k 1M 10M
1k
2
0
5
15
20
4
6
8 10
10
100
FREQUENCY – Hz
LOAD RESISTANCE – kΩ
SUPPLY VOLTAGE – ±Volts
Figure 18. Open-Loop Gain vs.
Figure 19. Open-Loop Gain and Phase Figure 20. Output Voltage Swing vs.
Load Resistance Over Temperature vs. Frequency
Supply Voltage
R
F
1000
+V
S
100
10
100
90
0.1 µF
A
= –1000
V
1/4
V
OUT
AD704
1
R
2kΩ
V
L
IN
C
L
A
= +1
V
0.1
10
0.1 µF
0%
SQUARE
WAVE INPUT
0.01
0.001
2V
50µs
I
= +1mA
OUT
–V
S
1
10
100
FREQUENCY – Hz
1k
10k
100k
Figure 21. Closed-Loop Output
Impedance vs. Frequency
Figure 22a. Unity Gain Follower
(For Large Signal Applications,
Resistor RF Limits the Current
Through the Input Protection
Diodes)
Figure 22b. Unity Gain Follower
Large Signal Pulse Response
RF = 10 kΩ, CL = 1,000 pF
10k
5µs
5µs
+V
S
100
90
100
90
0.1 µF
10k
V
IN
1/4
AD704
V
OUT
RL
2.5k
C
L
SQUARE
WAVE INPUT
10
10
0%
0%
0.1 µF
20mV
20mV
–V
S
Figure 23a. Unity Gain Inverter
Connection
Figure 22c. Unity Gain Follower
Small Signal Pulse Response
RF = 0 Ω, CL = 100 pF
Figure 22d. Unity Gain Follower
Small Signal Pulse Response
RF = 0 Ω, CL = 1,000 pF
–6–
REV. A
AD704
5µS
5µS
2V
50µs
100
90
100
90
100
90
10
10
10
0%
0%
0%
20mV
20mV
Figure 23c. Unity Gain Inverter
Small Signal Pulse Response,
CL = 100 pF
Figure 23d. Unity Gain Inverter Small
Signal Pulse Response, CL = 1,000 pF
Figure 23b. Unity Gain Inverter
Large Signal Pulse Response,
CL = 1,000 pF
C1
_ _
Q =
C3
_ _
4C2
GAIN TRIM
(500k POT)
1
OPTIONAL
AC CMRR TRIM
Q
=
=
4C4
2
1
_________
=
ω
1
_________
R6 C1C2
ω
R
47.5k
R4
49.9k
R2
2.4k
R5
6.34k
R3
6.34k
R1
G
R8 C3C4
R6 = R7
R8 = R9
+V
S
C
t
0.1 µF
C1
1MΩ
1MΩ
C3
DC
CMRR
TRIM
R6
R7
1MΩ
R8
1MΩ
R9
1/4
AD704
1/4
AD704
C2
1/4
AD704
OUTPUT
(5k POT)
1/4
AD704
C4
0.1 µF
–V
IN
IN
+V
–V
S
R10
C5
2MΩ
R11
C6
2MΩ
0.01µF
R2 2R2
R1
__
___
RG
INSTRUMENTATION AMPLIFIER GAIN = 1 +
+
(FOR R1 = R3, R2 = R4 + R5)
0.01µF
ALL RESISTORS METAL FILM, 1%
OPTIONAL BALANCE RESISTOR
NETWORKS CAN BE REPLACED
WITH A SHORT
CAPACITORS C2 AND C4 ARE
SOUTHERN ELECTRONICS MPCC,
POLYCARBONATE, ±5%, 50 VOLT
Figure 24. Gain of 10 Instrumentation Amplifier with Post Filtering
The instrumentation amplifier with post filtering (Figure 24)
Table I. Resistance Values for Various Gains
combines two applications which benefit greatly from the
AD704. This circuit achieves low power and dc precision over
temperature with a minimum of components.
Circuit Gain
(G)
RG (Max Value
of Trim Potentiometer) (–3 dB), Hz
Bandwidth
R1 & R3
The instrumentation amplifier circuit offers many performance
benefits including BiFET level input bias currents, low input
offset voltage drift and only 1.2 mA quiescent current. It will
operate for gains G ≥ 2, and at lower gains it will benefit from
the fact that there is no output amplifier offset and noise
contribution as encountered in a 3 op amp design. Good low
frequency CMRR is achieved even without the optional AC
CMRR trim (Figure 25). Table I provides resistance values for
3 common circuit gains. For other gains, use the following
equations:
10
100
1,000
6.34 kΩ
526 Ω
56.2 Ω
166 kΩ
16.6 kΩ
1.66 kΩ
50k
5k
0.5k
160
140
120
GAIN = 10, 0.2V p-p COMMON-MODE INPUT
CIRCUIT TRIMMED
USING CAPACITOR C
t
100
80
R2 = R4 + R5 = 49.9 kΩ
TYPICAL MONOLITHIC IN AMP
60
49.9 kΩ
0.9 G −1
R1 = R3 =
40
WITHOUT CAPACITOR C
t
20
0
99.8 k
0.06 G
Max Value of RG
=
1
1k
10k
10
100
FREQUENCY – Hz
Figure 25. Common-Mode Rejection vs. Frequency with
and without Capacitor Ct
1
Ct ≈
2 π (R3) 5 × 105
REV. A
–7–
AD704
180
120
The 1 Hz, 4-pole active filter offers dc precision with a mini-
mum of components and cost. The low current noise, IOS, and
IB allow the use of 1 MΩ resistors without sacrificing the
1 µV/°C drift of the AD704. This means lower capacitor values
may be used, reducing cost and space. Furthermore, since the
AD704’s IB is as low as its IOS, over most of the MIL tempera-
ture range, most applications do not require the use of the
normal balancing resistor (with its stability capacitor). Adding the
optional balancing resistor enhances performance at high
temperatures, as shown in Figure 26. Table II gives capacitor
values for several common low pass responses.
WITHOUT OPTIONAL
BALANCE RESISTOR, R3
60
0
WITH OPTIONAL
BALANCE RESISTOR, R3
–60
–120
–180
0
+120
–40
+40
+80
TEMPERATURE – oC
Figure 26. VOS vs. Temperature Performance of the 1 Hz
Filter Circuit
Table II. 1 Hz, 4-Pole Low-Pass Filter Recommended Component Values
Section 1
Frequency
(Hz)
Section 2
Frequency
(Hz)
Desired Low
Pass Response
C1
(F)
C2
(F)
C3
(F)
C4
(F)
Q
Q
Bessel
Butterworth
0.1 dB Chebychev
0.2 dB Chebychev
0.5 dB Chebychev
1.0 dB Chebychev
1.43
1.00
0.648
0.603
0.540
0.492
0.522
0.541
0.619
0.646
0.705
0.785
1.60
1.00
0.948
0.941
0.932
0.925
0.806
1.31
2.18
2.44
2.94
3.56
0.116
0.172
0.304
0.341
0.416
0.508
0.107
0.147
0.198
0.204
0.209
0.206
0.160
0.416
0.733
0.823
1.00
0.0616
0.0609
0.0385
0.0347
0.0290
0.0242
1.23
Specified Values are for a –3 dB point of 1.0 Hz. For other frequencies simply scale capacitors C1 through C4 directly; i.e., for 3 Hz Bessel response, C1 = 0.0387 µF,
C2 = 0.0357 µF, C3 = 0.0533 µF, C4 = 0.0205 µF.
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
14-Pin Cerdip (Q) Package
14-Pin Plastic DIP (N) Package
20-Terminal LCCC (E) Package
16-Pin Plastic SO (R) Package
0.100 (2.54)
0.064 (1.63)
0.358 (9.09)
0.342 (8.69)
0.040 (1.02)
x 45° REF
3 PLCS
0.028 (0.71)
0.022 (0.56)
NO. 1 PIN
INDEX
0.050
(1.27)
BSC
0.020 (0.51)
x 45° REF
–8–
REV. A
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