AD8220 Datasheet, PDF (1/28 Pages) Analog Devices – JFET Input Instrumentation Amplifier with Rail-to-Rail Output in MSOP Package

JFET Input Instrumentation Amplifier with
Rail-to-Rail Output in MSOP Package
AD8220
FEATURES
Low input currents
10 pA maximum input bias current (B grade)
0.6 pA maximum input offset current (B grade)
High CMRR
100 dB CMRR (minimum), G = 10 (B grade)
80 dB CMRR (minimum) to 5 kHz, G = 1 (B grade)
Excellent ac specifications and low power
1.5 MHz bandwidth (G = 1)
14 nV/√Hz input noise (1 kHz)
Slew rate 2 V/μs
750 μA quiescent supply current (maximum)
Versatile
MSOP package
Rail-to-rail output
Input voltage range to below negative supply rail
4 kV ESD protection
4.5 V to 36 V single supply
±2.25 V to ±18 V dual supply
Gain set with single resistor (G = 1 to 1000)
APPLICATIONS
Medical instrumentation
Precision data acquisition
Transducer interface
GENERAL DESCRIPTION
The AD8220 is the first single-supply JFET input
instrumentation amplifier available in an MSOP package.
Designed to meet the needs of high performance, portable
instrumentation, the AD8220 has a minimum common-mode
rejection ratio (CMRR) of 86 dB at dc and a minimum CMRR
of 80 dB at 5 kHz for G = 1. Maximum input bias current is 10
pA and typically remains below 300 pA over the entire
industrial temperature range. Despite the JFET inputs, the
AD8220 typically has a noise corner of only 10 Hz.
With the proliferation of mixed-signal processing, the number of
power supplies required in each system has grown. The AD8220 is
designed to alleviate this problem. The AD8220 can operate on a
±18 V dual supply, as well as on a single +5 V supply. Its rail-to-rail
output stage maximizes dynamic range on the low voltage supplies
common in portable applications. Its ability to run on a single 5 V
supply eliminates the need to use higher voltage, dual supplies. The
AD8220 draws a maximum of 750 μA of quiescent current, making
it ideal for battery-powered devices.
PIN CONFIGURATION
–IN 1
R_G 2
R_G 3
+IN 4
AD8220
8 +V_S
7 V_OUT
6 REF
5 –V_S
TOP VIEW
(Not to Scale)
Figure 1.
10n
1n
100p
10p
1p
0.1p
I_BIAS
I_OS
–50 –25
0
25
50
75 100 125 150
TEMPERATURE (°C)
Figure 2. Input Bias Current and Offset Current Temperature
Gain is set from 1 to 1000 with a single resistor. Increasing the
gain increases the common-mode rejection. Measurements that
need higher CMRR when reading small signals benefit when
the AD8220 is set for large gains.
A reference pin allows the user to offset the output voltage. This
feature is useful when interfacing with analog-to-digital
converters.
The AD8220 is available in an MSOP that takes roughly half the
board area of an SOIC. Performance is specified over the
industrial temperature range of −40°C to +85°C.
Rev. 0
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