Micropower, Single- and Dual-Supply,
Rail-to-Rail Instrumentation Amplifier
AD627
FEATURES
FUNCTIONAL BLOCK DIAGRAM
Micropower, 85 μA maximum 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 1000
Higher performance than discrete designs
Rail-to-rail output swing
High accuracy dc performance
AD627
R
1
2
3
4
8
7
6
5
R
G
G
–IN
+IN
+V
S
OUTPUT
REF
–V
S
Figure 1. 8-Lead PDIP (N) and SOIC_N (R)
100
90
80
70
60
50
40
30
20
10
0
0.03% typical gain accuracy (G = +5) (AD627A)
10 ppm/°C typical gain drift (G = +5)
125 μV maximum input offset voltage (AD627B dual supply)
200 μV maximum input offset voltage (AD627A dual supply)
1 μV/°C maximum input offset voltage drift (AD627B)
3 μV/°C maximum input offset voltage drift (AD627A)
10 nA maximum input bias current
Noise: 38 nV/√Hz RTI noise @ 1 kHz (G = +100)
Excellent ac specifications
AD627A: 77 dB minimum CMRR (G = +5)
AD627B: 83 dB minimum CMRR (G = +5)
80 kHz bandwidth (G = +5)
AD627
TRADITIONAL
LOW POWER
DISCRETE DESIGN
135 μs settling time to 0.01% (G = +5, 5 V step)
1
10
100
1k
10k
FREQUENCY (Hz)
Figure 2. CMRR vs. Frequency, ±± ꢀS, Gain = +±
APPLICATIONS
4 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
ideal for battery-powered applications. Its rail-to-rail output
stage maximizes dynamic range when operating from low
supply voltages. Dual-supply operation (±±5 Vꢀ and low power
consumption make the AD627 ideal for industrial applications,
including 4 to 20 mA loop-powered systems.
GENERAL DESCRIPTION
The AD627 is an integrated, micropower instrumentation
amplifier that delivers rail-to-rail output swing on single and
dual (+2.2 V to ±±1 Vꢀ supplies. The AD627 provides excellent
ac and dc specifications while operating at only 15 μA maximum.
The AD627 does not compromise performance, unlike other
micropower instrumentation amplifiers. Low voltage offset,
offset drift, gain error, and gain drift minimize errors in the
system. The AD627 also minimizes errors over frequency by
providing excellent CMRR over frequency. Because the CMRR
remains high up to 200 Hz, line noise and line harmonics are
rejected.
The AD627 offers superior flexibility by allowing the user to set
the gain of the device with a single external resistor while con-
forming to the 1-lead industry-standard pinout configuration.
With no external resistor, the AD627 is configured for a gain of 5.
With an external resistor, it can be set to a gain of up to ±000.
A wide supply voltage range (+2.2 V to ±±1 Vꢀ and micropower
current consumption make the AD627 a perfect fit for a wide
range of applications. Single-supply operation, low power
consumption, and rail-to-rail output swing make the AD627
The AD627 provides superior performance, uses less circuit
board area, and costs less than micropower discrete designs.
Rev. D
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