AD8293G80 Datasheet, PDF (1/16 Pages) Analog Devices – Low Cost, Zero-Drift In-Amp with Filter and Fixed Gain

FEATURES
Small package: 8-lead SOT-23
Reduced component count
Incorporates gain resistors and filter resistors
Low offset voltage: 20 μV maximum
Low offset drift: 0.3 μV/°C maximum
Low gain drift: 25 ppm/°C maximum
High CMR: 140 dB typical
Low noise: 0.7 μV p-p from 0.01 Hz to 10 Hz
Single-supply operation: 1.8 V to 5.5 V
Rail-to-rail output
Available in 2 fixed-gain models
APPLICATIONS
Current sensing
Strain gauges
Laser diode control loops
Portable medical instruments
Thermocouple amplifiers
GENERAL DESCRIPTION
The AD8293G80/AD8293G160 are small, low cost, precision
instrumentation amplifiers that have low noise and rail-to-rail
outputs. They are available in two fixed-gain models: 80 and 160.
They incorporate the gain setting resistors and filter resistors,
reducing the number of ancillary components. For example,
only two external capacitors are needed to implement a 2-pole
filter. The AD8293G80/AD8293G160 also feature low offset
voltage, offset drift, and gain drift coupled with high common-
mode rejection. They are capable of operating on a supply of
1.8 V to 5.5 V.
With a low offset voltage of 20 μV (AD8293G160B), an offset
voltage drift of 0.3 μV/°C, and a voltage noise of only 0.7 μV p-p
(0.01 Hz to 10 Hz), the AD8293G80/AD8293G160 are ideal
for applications where error sources cannot be tolerated.
Low Cost, Zero-Drift In-Amp
with Filter and Fixed Gain
AD8293G80/AD8293G160
FUNCTIONAL BLOCK DIAGRAM
7
+V_S
5
6
FILT OUT
+IN
8
R1
4kΩ
–IN
1
R2
IN-AMP
R3
5kΩ
4
ADC OUT
GND REF
2
3
AD8293Gxx
Figure 1.
OUTPUT TO ADC
WITH ANTIALIASING
FILTER
+5V
0.1µF
C2
7
+V_S
5
6
FILT OUT
LOAD
R2
+IN
8
I
R1
R_{SHUNT 4kΩ}
IN-AMP
1.8V
–IN
1
DC-DC
GND REF
2
3
R3
5kΩ
4
ADC OUT
AD8293Gxx
ADC
C3
REF
+3.3V
0.1µF
10µF
Figure 2. Measuring Current Using the AD8293G80/AD8293G160
Table 1. AD8293Gxx Models and Gains
Model
Gain
AD8293G80
80
AD8293G160
160
Precision instrumentation, position and pressure sensors,
medical instrumentation, and strain gauge amplifiers benefit
from the low noise, low input bias current, and high common-
mode rejection. The small footprint and low cost are ideal for
high volume applications.
The small package and low power consumption allow the maxi-
mum channel density and the minimum board size required for
portable systems. Designed for ease of use, these instrumentation
amplifiers, unlike more traditional ones, have a buffered reference,
eliminating the need for an additional op amp to set the reference
voltage to midsupply.
The AD8293G80/AD8293G160 are specified over the industrial
temperature range from −40°C to +85°C. The AD8293G80/
AD8293G160 are available in a halogen-free, Pb-free, 8-lead SOT-23.
Rev. 0
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