AD8221 Datasheet, PDF (1/20 Pages) Analog Devices – Precision Instrumentation Amplifier

Precision Instrumentation Amplifier
AD8221
FEATURES
Available in space-saving MSOP package
Gain set with 1 external resistor (gain range 1 to 1000)
Wide power supply range: ±2.3 V to ±18 V
Temperature range for specified performance:
–40°C to +85°C
Operational up to 125°C¹
EXCELLENT AC SPECIFICATONS
80 dB min CMRR to 10 kHz ( G = 1)
825 kHz –3 dB bandwidth (G = 1)
2 V/µs slew rate
LOW NOISE
8 nV/√Hz, @ 1 kHz, max input voltage noise
0.25 µV p-p input noise (0.1 Hz to 10 Hz)
HIGH ACCURACY DC PERFORMANCE (AD8221BR)
90 dB min CMRR (G = 1)
25 µV max input offset voltage
0.3 µV/°C max input offset drift
0.4 nA max input bias current
APPLICATIONS
Weigh scales
Industrial process controls
Bridge amplifiers
Precision data acquisition systems
Medical instrumentation
Strain gages
Transducer interfaces
GENERAL DESCRIPTION
The AD8221 is a gain programmable, high performance instru-
mentation amplifier that delivers the industry’s highest CMRR
over frequency. The CMRR of instrumentation amplifiers on
the market today falls off at 200 Hz. In contrast, the AD8221
maintains a minimum CMRR of 80 dB to 10 kHz for all grades
at G = 1. High CMRR over frequency allows the AD8221 to
reject wideband interference and line harmonics, greatly
simplifying filter requirements. Possible applications include
precision data acquisition, biomedical analysis, and aerospace
instrumentation.
Low voltage offset, low offset drift, low gain drift, high gain
accuracy, and high CMRR make this part an excellent choice in
applications that demand the best dc performance possible,
such as bridge signal conditioning.
CONNECTION DIAGRAM
–IN ¹
R_G 2
R_G 3
+IN 4
AD8221
TOP VIEW
8 +V_S
7 V_OUT
6 REF
5 –V_S
Figure 1. SOIC and MSOP Connection Diagram
120
110
100
90
80
70
60
50
40
10
AD8221
COMPETITOR 1
COMPETITOR 2
100
1k
10k
FREQUENCY (Hz)
100k
Figure 2. Typical CMRR vs. Frequency for G = 1
Programmable gain affords the user design flexibility. A single
resistor sets the gain from 1 to 1000. The AD8221 operates on
both single and dual supplies, and is well suited for applications
where ±10 V input voltages are encountered.
The AD8221 is available in low cost 8-lead SOIC and MSOP
packages, both of which offer the industry’s best performance.
The MSOP requires half the board space of the SOIC, making it
ideal for multichannel or space-constrained applications.
Performance is specified over the entire industrial temperature
range of –40°C to +85°C for all grades. Furthermore, the
AD8221 is operational from –40°C to +125°C¹.
1 _{See Typical Performance Curves for expected operation from 85°C to 125°C.}
Rev. A
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