JFET Input Instrumentation Amplifier with
Rail-to-Rail Output in MSOP Package
Low input currents
10 pA maximum input bias current (B grade)
0.6 pA maximum input offset current (B grade)
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)
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)
Qualified for automotive applications
Precision data acquisition
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. Maxi-
mum 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.
(Not to Scale)
0 25 50 75 100 125 150
Figure 2. Input Bias Current and Offset Current vs. 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 for the A and B grade is
specified over the industrial temperature range of −40°C to +85°C,
and the W grade is specified over the automotive temperature
range of −40°C to +125°C.
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 that may result from its use. Specifications subject to change without notice. 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.
Fax: 781.461.3113 ©2006–2010 Analog Devices, Inc. All rights reserved.