AD626 Datasheet, PDF (1/12 Pages) Analog Devices – Low Cost, Single Supply Differential Amplifier

a
Low Cost, Single Supply
Differential Amplifier
AD626
FEATURES
Pin Selectable Gains of 10 and 100
True Single Supply Operation
Single Supply Range of +2.4 V to +10 V
Dual Supply Range of ؎1.2 V to ؎6 V
Wide Output Voltage Range of 30 mV to 4.7 V
Optional Low-Pass Filtering
Excellent DC Performance
Low Input Offset Voltage: 500 ␮V max
Large Common-Mode Range: 0 V to +54 V
Low Power: 1.2 mW (V_S = +5 V)
Good CMR of 90 dB typ
AC Performance
Fast Settling Time: 24 ␮s (0.01%)
Includes Input Protection
Series Resistive Inputs (R_IN = 200 k⍀)
RFI Filters Included
Allows 50 V Continuous Overload
APPLICATIONS
Current Sensing
Interface for Pressure Transducers, Position Indicators,
Strain Gages, and Other Low Level Signal Sources
PRODUCT DESCRIPTION
The AD626 is a low cost, true single supply differential ampli-
fier designed for amplifying and low-pass filtering small differen-
tial voltages from sources having a large common-mode voltage.
The AD626 can operate from either a single supply of +2.4 V to
+10 V, or dual supplies of ± 1.2 V to ± 6 V. The input common-
mode range of this amplifier is equal to 6 (+V_S – 1 V) which
provides a +24 V CMR while operating from a +5 V supply.
Furthermore, the AD626 features a CMR of 90 dB typ.
160
CONNECTION DIAGRAM
8-Lead Plastic Mini-DIP (N)
and SOIC (SO) Packages
–IN 1
ANALOG
GND
2
200k⍀
1/6
G = 30
200k⍀
8 +IN
7 G = 100
–V_S 3
FILTER 4
100k⍀
AD626
G=2
6 +VS
5 OUT
The amplifier’s inputs are protected against continuous overload
of up to 50 V, and RFI filters are included in the attenuator
network. The output range is +0.03 V to +4.9 V using a +5 V
supply. The amplifier provides a preset gain of 10, but gains be-
tween 10 to 100 can be easily configured with an external resis-
tor. Furthermore, a gain of 100 is available by connecting the G
= 100 pin to analog ground. The AD626 also offers low-pass
filter capability by connecting a capacitor between the filter pin
and analog ground.
The AD626A and AD626B operate over the industrial tempera-
ture range of –40°C to +85°C. The AD626 is available in two
8-lead packages: a plastic mini-DIP and SOIC.
25
140
100
G = 10,100
V_S = +5V
80
G = 100
60
V_S = ؎5V
40
G = 10
V_S = ؎5V
20
0
0.1
1
10
100
1k
10k 100k 1M
FREQUENCY – Hz
Common-Mode Rejection vs. Frequency
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.
20
15
؎V_CM FOR SINGLE
AND DUAL SUPPLIES
10
5
؎V_CM FOR DUAL
SUPPLIES ONLY
0
1
2
3
4
5
POWER SUPPLY VOLTAGE – ؎Volts
Input Common-Mode Range vs. Supply
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© Analog Devices, Inc., 1999