a
Micropower, Single and Dual Supply
Rail-to-Rail Instrumentation Amplifier
AD627
FUNCTIONAL BLOCK DIAGRAM
8-Lead Plastic DIP (N) and SOIC (R)
R
G 1
–IN
2
+IN
3
–V
S 4
8
R
G
7
+V
S
6
OUTPUT
FEATURES
Micropower, 85 A Max Supply Current
Wide Power Supply Range (+2.2 V to 18 V)
Easy to Use
Gain Set with One External Resistor
Gain Range 5 (No Resistor) to 1,000
Higher Performance than Discrete Designs
Rail-to-Rail Output Swing
High Accuracy DC Performance
0.10% Gain Accuracy (G = 5) (AD627A)
10 ppm Gain Drift (G = 5)
125 V Max Input Offset Voltage (AD627B)
200 V Max Input Offset Voltage (AD627A)
1 V/ C Max Input Offset Voltage Drift (AD627B)
3 V/ C Max Input Offset Voltage Drift (AD627A)
10 nA Max Input Bias Current
Noise: 38 nV/√Hz RTI Noise @ 1 kHz (G = 100)
Excellent AC Specifications
77 dB Min CMRR (G = 5) (AD627A)
83 dB Min CMRR (G = 5) (AD627B)
80 kHz Bandwidth (G = 5)
135 s Settling Time to 0.01% (G = 5, 5 V Step)
APPLICATIONS
4 mA-to-20 mA Loop Powered Applications
Low Power Medical Instrumentation—ECG, EEG
Transducer Interfacing
Thermocouple Amplifiers
Industrial Process Controls
Low Power Data Acquisition
Portable Battery Powered Instruments
PRODUCT DESCRIPTION
AD627
5
REF
Wide supply voltage range (+2.2 V to
±
18 V), and micropower
current consumption make the AD627 a perfect fit for a wide
range of applications. Single supply operation, low power con-
sumption and rail-to-rail output swing make the AD627 ideal
for battery powered applications. Its rail-to-rail output stage
maximizes dynamic range when operating from low supply
voltages. Dual supply operation (± 15 V) and low power con-
sumption make the AD627 ideal for industrial applications,
including 4 mA-to-20 mA loop-powered systems.
The AD627 does not compromise performance, unlike other
micropower instrumentation amplifiers. Low voltage offset,
offset drift, gain error, and gain drift keep dc errors to a mini-
mum in the users system. The AD627 also holds errors over
frequency to a minimum by providing excellent CMRR over
frequency. Line noise, as well as line harmonics, will be rejected,
since the CMRR remains high up to 200 Hz.
The AD627 provides superior performance, uses less circuit
board area and does it for a lower cost than micropower discrete
designs.
100
CMRR – dB
The AD627 is an integrated, micropower, instrumentation
amplifier that delivers rail-to-rail output swing on single and
dual (+2.2 V to
±
18 V) supplies. The AD627 provides the user
with excellent ac and dc specifications while operating at only
85
µA
max.
The AD627 offers superior user flexibility by allowing the user
to set the gain of the device with a single external resistor, and
by conforming to the 8-lead industry standard pinout configura-
tion. With no external resistor, the AD627 is configured for a
gain of 5. With an external resistor, it can be programmed for
gains of up to 1000.
AD627
90
80
70
60
50
40
30
20
10
0
1
10
100
FREQUENCY – Hz
1k
10k
TRADITIONAL
LOW POWER
DISCRETE DESIGN
Figure 1. CMRR vs. Frequency,
±
5 V
S
, Gain = 5
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: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 1999
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