
FUNCTIONAL BLOCK DIAGRAM
AD22050
OUT
GND
IN+
IN–
+VS
OFS
A1
A2
A1
A2
REV. 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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
a
Single-Supply Sensor
Interface Amplifier
AD22050
GENERAL DESCRIPTION
The AD22050 is a single-supply difference amplifier for ampli-
fying and low-pass filtering small differential voltages (typically
100 mV FS at a gain of 40) from sources having a large common-
mode voltage.
Supply voltages from +3.0 V to +36 V can be used. The input
common-mode range extends from below ground to +24 V using
FEATURES
Gain of
20. Alterable from
1 to
160
Input CMR from Below Ground to 6
(VS – 1 V)
Output Span 20 mV to (VS – 0.2) V
1-, 2-, 3-Pole Low-Pass Filtering Available
Accurate Midscale Offset Capability
Differential Input Resistance 400 k
Drives 1 k
Load to +4 V Using VS = +5 V
Supply Voltage: +3.0 V to +36 V
Transient Spike Protection and RFI Filters Included
Peak Input Voltage (40 ms): 60 V
Reversed Supply Protection: –34 V
Operating Temperature Range: –40 C to +125 C
APPLICATIONS
Current Sensing
Motor Control
Interface for Pressure Transducers, Position Indicators,
Strain Gages, and Other Low Level Signal Sources
a +5 V supply with excellent rejection of this common-mode
voltage. This is achieved by the use of a special resistive attenua-
tor at the input, laser trimmed to a very high differential balance.
Provisions are included for optional low-pass filtering and gain
adjustment. An accurate midscale offset feature allows bipolar
signals to be amplified.
AD22050
SINGLE-POLE LOW-PASS FILTERING, GAIN: 40
POWER
DARLINGTON
100m
200k
C
+5V
ANALOG OUTPUT
4V PER AMP
CORNER FREQUENCY
= 0.796Hz- F
ANALOG GROUND
SOLENOID
LOAD
+VS (CAR BATTERY)
CMOS DRIVER
CHASSIS
Figure 1. Typical Application Circuit for a Current Sensor Interface
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
Analog Devices, Inc., 1999