a
FEATURES
EASY TO USE
Gain Set with One External Resistor
(Gain Range 1 to 1000)
Wide Power Supply Range ( 2.3 V to 18 V)
Higher Performance than Three Op Amp IA Designs
Available in 8-Lead DIP and SOIC Packaging
Low Power, 1.3 mA max Supply Current
EXCELLENT DC PERFORMANCE (鈥淏 GRADE鈥?
50 V max, Input Offset Voltage
0.6 V/ C max, Input Offset Drift
1.0 nA max, Input Bias Current
100 dB min Common-Mode Rejection Ratio (G = 10)
LOW NOISE
9 nV/鈭欻z, @ 1 kHz, Input Voltage Noise
0.28 V p-p Noise (0.1 Hz to 10 Hz)
EXCELLENT AC SPECIFICATIONS
120 kHz Bandwidth (G = 100)
15 s Settling Time to 0.01%
APPLICATIONS
Weigh Scales
ECG and Medical Instrumentation
Transducer Interface
Data Acquisition Systems
Industrial Process Controls
Battery Powered and Portable Equipment
PRODUCT DESCRIPTION
Low Cost, Low Power
Instrumentation Amplifier
AD620
CONNECTION DIAGRAM
8-Lead Plastic Mini-DIP (N), Cerdip (Q)
and SOIC (R) Packages
R
G
鈥揑N
+IN
鈥揤
S
1
2
3
4
8
R
G
7 +V
S
6 OUTPUT
AD620
TOP VIEW
5 REF
1000. Furthermore, the AD620 features 8-lead SOIC and DIP
packaging that is smaller than discrete designs, and offers lower
power (only 1.3 mA max supply current), making it a good fit
for battery powered, portable (or remote) applications.
The AD620, with its high accuracy of 40 ppm maximum
nonlinearity, low offset voltage of 50
碌V
max and offset drift of
0.6
碌V/擄C
max, is ideal for use in precision data acquisition
systems, such as weigh scales and transducer interfaces. Fur-
thermore, the low noise, low input bias current, and low power
of the AD620 make it well suited for medical applications such
as ECG and noninvasive blood pressure monitors.
The low input bias current of 1.0 nA max is made possible with
the use of Super尾eta processing in the input stage. The AD620
works well as a preamplifier due to its low input voltage noise of
9 nV/鈭欻z at 1 kHz, 0.28
碌V
p-p in the 0.1 Hz to 10 Hz band,
0.1 pA/鈭欻z input current noise. Also, the AD620 is well suited
for multiplexed applications with its settling time of 15
碌s
to
0.01% and its cost is low enough to enable designs with one in-
amp per channel.
10,000
The AD620 is a low cost, high accuracy instrumentation ampli-
fier that requires only one external resistor to set gains of 1 to
30,000
TOTAL ERROR, PPM OF FULL SCALE
25,000
3 OP-AMP
IN-AMP
(3 OP-07s)
1,000
20,000
RTI VOLTAGE NOISE
(0.1 鈥?10Hz) 鈥?V p-p
TYPICAL STANDARD
BIPOLAR INPUT
IN-AMP
100
G = 100
10
AD620 SUPER ETA
BIPOLAR INPUT
IN-AMP
15,000
AD620A
10,000
R
G
5,000
1
0
0
5
10
SUPPLY CURRENT 鈥?mA
15
20
0.1
1k
10k
100k
1M
SOURCE RESISTANCE 鈥?/div>
10M
100M
Figure 1. Three Op Amp IA Designs vs. AD620
Figure 2. Total Voltage Noise vs. Source Resistance
REV. E
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: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
漏 Analog Devices, Inc., 1999
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