Analog Devices AD704 c Datasheet

Quad Picoampere Input Current

2

3

11

10

12

13

14

15

16

9

1

2

3

4

5

6

7

8

NC = NO CONNECT

NC

1

4

OUTPUT

–IN

–IN

OUTPUT

OUTPUT

–IN

–IN

OUTPUT

AD704

(TOP VIEW)

+IN

+IN

+IN

+V

S

–V

S

+IN

NC

a

FEATURES
High DC Precision

75 ␮V Max Offset Voltage
1 ␮V/ⴗC Max Offset Voltage Drift
150 pA Max Input Bias Current

0.2 pA/ⴗC Typical I

Drift

B

Low Noise

0.5 ␮V p-p Typical Noise, 0.1 Hz to 10 Hz

Low Power

600 ␮A Max Supply Current per Amplifier
MIL-STD-883B Processing Available
Available in Tape and Reel in Accordance

with EIA-481A Standard
Dual Version: AD706

APPLICATIONS
Industrial/Process Controls
Weigh Scales
ECG/EKG Instrumentation
Low Frequency Active Filters

PRODUCT DESCRIPTION

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 I

drift over temperature. It utilizes super-beta

B

bipolar input transistors to achieve picoampere input bias current
levels (similar to FET input amplifiers at room temperature),
while its I
BiFET amp, for which I

typically only increases by 5× at 125°C (unlike a

B

doubles every 10°C resulting in a

B

1000× increase at 125°C). Furthermore, the AD704 achieves
75 µV offset voltage and low noise characteristics of a precision
bipolar input op amp.

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.

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
is 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.

REV. C

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 that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices.

14-Lead CerDIP (Q) Packages

OUTPUT

OUTPUT

Bipolar Op Amp

AD704

CONNECTION DIAGRAMS

14-Lead Plastic DIP (N)

14

OUTPUT

13

4

3

–IN

12

+IN

11

–V

10

9

8

S

+IN

–IN

OUTPUT

)

+V

–IN

+IN

+IN

–IN

1

2

1

3

AD704

4

S

5

6

7

(TOP VIEW

2

20-Terminal LCC

(E) Package

–IN1

OUT1

3212019

4

+IN1

5

NC

+V

6

S

7

NC

8

+IN2

910111213

100

10

– nA

B

1

TYPICAL I

0.1

0.01
–55 +25 +125

NC

AMP 1

AD704

AMP 2

–IN2

OUT2NCOUT3

TEMPERATURE – C

Figure 1. Input Bias Current Over Temperature

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]www.analog.com
Fax: [phone] © Analog Devices, Inc., 2002

16-Lead SOIC

(R) Package

–IN4

OUT4

18

AMP 4

AMP 3

TYPICAL JFET AMP

17

16

15

14

–IN3

NC = NO CONNECT

AD704T

+IN4

NC

–V

NC

+IN3

S

AD704–SPECIFICATIONS

(@ TA = 25ⴗC, VCM = 0 V, and ⴞ15 V dc, unless otherwise noted.)

AD704J/A AD704K AD704T

Parameters Conditions Min Typ Max Min Typ Max Min Typ Max Unit

INPUT OFFSET VOLTAGE

Initial Offset 50 150 30 75 30 100 µV
Offset T

MIN–TMAX

100 250 50 150 80 150 µV

vs. Temp, Average TC 0.2 1.5 0.2 1.0 1.0 µV/°C
vs. Supply (PSRR) VS = ±2 to ± 18 V 100 132 112 132 112 132 dB

T

MIN–TMAX

VS = ±2.5 to ± 18 V 100 126 108 126 108 126 dB

Long-Term Stability 0.3 0.3 0.3 µV/month

INPUT BIAS CURRENT

1

VCM = 0 V 100 270 80 150 80 200 pA

= ±13.5 V 300 200 250 pA

V

CM

vs. Temp, Average TC 0.3 0.2 1.0 pA/°C

T

MIN–TMAX

VCM = 0 V 300 200 600 pA
VCM = ±13.5 V 400 300 700 pA

INPUT OFFSET CURRENT V

= 0 V 80 250 30 100 50 150 pA

CM

= ±13.5 V 300 150 200 pA

V

CM

vs. Temp, Average TC 0.6 0.4 0.4 pA/°C

T

MIN–TMAX

VCM = 0 V 100 300 80 200 80 400 pA
VCM = ±13.5 V 100 400 80 300 100 500 pA

MATCHING CHARACTERISTICS

Offset Voltage 250 130 150 µV

Input Bias Current

2

Common-Mode Rejection

Power Supply Rejection

Crosstalk

5

4

T

MIN–TMAX

T

3

MIN–TMAX

T

MIN–TMAX

94 110 104 dB
94 104 104 dB
94 110 110 dB

T

MIN–TMAX

94 106 106 dB
f = 10 Hz
R

= 2 kΩ 150 150 150 dB

LOAD

400 200 250 µV
500 300 400 pA
600 400 600 pA

FREQUENCY RESPONSE

UNITY GAIN

Crossover Frequency 0.8 0.8 0.8 MHz
Slew Rate, Unity Gain G = –1 0.15 0.15 0.15 V/µs
Slew Rate T

MIN–TMAX

0.1 0.1 0.1 V/µs

INPUT IMPEDANCE

Differential 40储240储240储2MΩ储pF
Common-Mode 300储2 300储2 300储2GΩ储pF

INPUT VOLTAGE RANGE

Common-Mode Voltage ±13.5 ± 14 ±13.5 ±14 ±13.5 ± 14 V
Common-Mode Rejection Ratio V

= ±13.5 V 100 132 114 132 110 132 dB

CM

T

MIN–TMAX

98 128 108 128 108 128 dB

INPUT CURRENT NOISE 0.1 to 10 Hz 3 3 3 pA p-p

f = 10 Hz 50 50 50 fA/√Hz

INPUT VOLTAGE NOISE 0.1 to 10 Hz 0.5 0.5 2.0 0.5 2.0 µV p-p

f = 10 Hz 17 17 17 nV/√Hz
f = 1 kHz 15 22 15 22 15 22 nV/√Hz

OPEN-LOOP GAIN V

= ±12 V

O

= 10 kΩ 200 2000 400 2000 400 2000 V/mV

R

LOAD

T

MIN–TMAX

= ±10 V

V

O

= 2 kΩ 200 1000 300 1000 200 1000 V/mV

R

LOAD

T

MIN–TMAX

150 1500 300 1500 300 1500 V/mV

150 1000 200 1000 100 1000 V/mV

–2–

REV. C

AD704

Parameters Conditions Min Typ Max Min Typ Max Min Typ Max Unit

AD704J/A AD704K AD704T

OUTPUT CHARACTERISTICS

Voltage Swing R

= 10 kΩ

LOAD

T

MIN–TMAX

±13 ±14 ± 13 ±14 ±13 ±14 V

Current Short Circuit ±15 ±15 ±15 mA

CAPACITIVE LOAD

Drive Capability Gain = 1 10,000 10,000 10,000 pF

POWER SUPPLY

Rated Performance ±15 ±15 ±15 V
Operating Range ±2.0 ±18 ±2.0 ±18 ±2.0 ±18 V
Quiescent Current 1.5 2.4 1.5 2.4 1.5 2.4 mA

T

MIN–TMAX

1.6 2.6 1.6 2.6 1.6 2.6 mA

TRANSISTOR COUNT # of Transistors 180 180 180

NOTES

1

Bias current specifications are guaranteed maximum at either input.

2

Input bias current match is the maximum difference between corresponding inputs of all four amplifiers.

3

CMRR match is the difference of ∆VOS/∆VCM between any two amplifiers, expressed in dB.

4

PSRR match is the difference between ∆VOS/∆V

5

See Figure 2a for test circuit.

All min and max specifications are guaranteed.

Specifications subject to change without notice.

for any two amplifiers, expressed in dB.

SUPPLY

REV. C

–3–

AD704

1/4

AD704

OUTPUT

INPUT*
SIGNAL

9k⍀

1k⍀

1k⍀

2.5k⍀

–

+

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.

AD704
PIN 4

AD704
PIN 11

COM

0.1␮F

1␮F

0.1␮F

1␮F

+V

S

–V

S

WARNING!

ESD SENSITIVE DEVICE

ABSOLUTE MAXIMUM RATINGS

1

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 18 V

Internal Power Dissipation (25°C) . . . . . . . . . . . . See Note 2

Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± V

S

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C

AD704T . . . . . . . . . . . . . . . . . . . . . . . . . –55°C to +125°C

Lead Temperature Range (Soldering 10 seconds) . . . . . 300°C

NOTES

1

Stresses above those listed under Absolute Maximum Ratings may cause perma-

nent damage to the device. This is a stress rating only; 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.

2

Specification is for device in free air:

14-Lead Plastic Package: θJA = 150°C/W
14-Lead Cerdip Package: θJA = 110°C/W
16-Lead SOIC Package: θJA = 100°C/W
20-Terminal LCC Package: θJA = 150°C/W

3

The 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.

Figure 2a. Crosstalk Test Circuit

–80

–100

AMP2

–120

CROSSTALK – dB

–140

–160

10 100 1k 10k 100k

FREQUENCY – Hz

Figure 2b. Crosstalk vs. Frequency

AMP4

AMP3

ORDERING GUIDE

Model Temperature Range Package Description Package Option

AD704JN 0°C to 70°C Plastic N-14
AD704JR 0°C to 70°C Small Outline (SOIC) R-16
AD704JR-/REEL 0°C to 70°C Tape and Reel
AD704KN
AD704AN

*

*

0°C to 70°C Plastic N-14

–40°C to +85°C Plastic N-14
AD704AR –40°C to +85°C Small Outline (SOIC) R-16
AD704AR-REEL –40°C to +85°C Tape and Reel
AD704SE/883B –55°C to +125°C Leadless Ceramic Chip Carrier E-20A
AD704TQ/883B

Chips are also available.

*Not for new designs; obsolete April 2002.

*

–55°C to +125°C Cerdip Q-14

CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although
the AD704 features proprietary ESD protection circuitry, permanent damage may occur on devices
subjected to high-energy electrostatic discharges. Therefore, proper ESD precautions are
recommended to avoid performance degradation or loss of functionality.

–4–

REV. C