Preliminary Technical Data
FEATURES
2 channels in a small, 4 mm × 4 mm LFCSP
LFCSP package has no metal pad
More routing room
No current leakage to pad
Gain set with 1 external resistor
Gain range: 1 to 1000
Input voltage goes below ground
Inputs protected beyond supplies
Very wide power supply range
Single supply: 2.2 V to 36 V
Dual supply: ±1.35 V to ±18 V
Bandwidth (G = 1): 1.5 MHz
CMRR (G = 1): 80 dB minimum
Input noise: 22 nV/√Hz
Typical supply current (per amp): 350 μA
Specified temperature range: −40°C to +125°C
Wide Supply Range, Rail-to-Rail
Output Instrumentation Amplifier
AD8426
PIN CONFIGURATION
OUT1
OUT2
+V
S
16 15 14 13
AD8426
–IN1 1
RG1 2
RG1 3
+IN1 4
12 –IN2
11 RG2
10 RG2
9
+IN2
5
+V
S
6
REF1
7
REF2
–V
S
8
09490-001
Figure 1.
Table 1. Instrumentation Amplifiers by Category
1
General
Purpose
AD8220
AD8221
AD8222
AD8224
AD8228
AD8295
Zero
Drift
AD8231
AD8290
AD8293
AD8553
AD8556
AD8557
Military
Grade
AD620
AD621
AD524
AD526
AD624
Low
Power
AD627
AD623
AD8235
AD8236
AD8426
AD8226
AD8227
High Speed
PGA
AD8250
AD8251
AD8253
APPLICATIONS
Industrial process controls
Bridge amplifiers
Medical instrumentation
Portable data acquisition
Multichannel systems
1
See
www.analog.com
for the latest instrumentation amplifiers.
GENERAL DESCRIPTION
The
AD8426
is a dual channel, low cost, wide supply range
instrumentation amplifier that requires only one external
resistor to set any gain from 1 to 1000.
The
AD8426
is designed to work with a variety of signal
voltages. A wide input range and rail-to-rail output allow the
signal to make full use of the supply rails. Because the input
range also includes the ability to go below the negative supply,
small signals near ground can be amplified without requiring
dual supplies. The
AD8426
operates on supplies ranging from
±1.35 V to ±18 V for dual supplies and 2.2 V to 36 V for single
supply.
The robust
AD8426
inputs are designed to connect to real-
world sensors. In addition to its wide operating range, the
AD8426
can handle voltages beyond the rails. For example,
with a ±5 V supply, the part is guaranteed to withstand ±35 V
at the input with no damage. Minimum as well as maximum input
Rev. PrD
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.
Trademarks and registered trademarks are the property of their respective owners.
bias currents are specified to facilitate open-wire detection.
The
AD8426
is designed to make PCB routing easy and
efficient. The two amplifiers are arranged in a logical way
so that typical application circuits have short routes and few
vias. Unlike most chip scale packages, the
AD8426
does not
have an exposed metal pad on the back of the part, which frees
additional space for routing and vias. The
AD8426
offers two in
amps in the equivalent board space of a typical MSOP package.
The
AD8426
is ideal for multichannel, space-constrained
industrial applications. Unlike other low cost, low power
instrumentation amplifiers, the
AD8426
is designed with a
minimum gain of 1 and can easily handle ±10 V signals. With
its space-saving LFCSP package and 125°C temperature rating,
the
AD8426
thrives in tightly packed, zero airflow designs.
The
AD8226
is the single channel version of the
AD8426.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2011 Analog Devices, Inc. All rights reserved.
–V
S
AD8426
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
Pin Configuration ............................................................................. 1
General Description ......................................................................... 1
Specifications..................................................................................... 3
Dual-Supply Operation ............................................................... 3
Single-Supply Operation ............................................................. 5
Absolute Maximum Ratings............................................................ 8
Thermal Resistance ...................................................................... 8
ESD Caution .................................................................................. 8
Pin Configuration and Function Descriptions ............................. 9
Typical Performance Characteristics ........................................... 10
Theory of Operation ...................................................................... 11
Architecture................................................................................. 11
Preliminary Technical Data
Gain Selection ..............................................................................11
Reference Terminal .....................................................................11
Input Voltage Range ................................................................... 12
Layout .......................................................................................... 12
Input Bias Current Return Path ............................................... 13
Input Protection ......................................................................... 13
Radio Frequency Interference (RFI) ........................................ 14
Applications Information .............................................................. 15
Differential Drive ....................................................................... 15
Precision Strain Gage ................................................................. 16
Driving an ADC.......................................................................... 16
Outline Dimensions ....................................................................... 17
Rev. PrD | Page 2 of 20
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