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 (VS = +5 V)
Good CMR of 90 dB Typ
AC Performance
Fast Settling Time: 24 s (0.01%)
Includes Input Protection
Series Resistive Inputs (RIN = 200 k⍀)
RFI Filters Included
Allows 50 V Continuous Overload
CONNECTION DIAGRAM
8-Lead Plastic Mini-DIP (N)
and SOIC (R) Packages
200k⍀
–IN
ANALOG
GND
+IN
7
G = 100
6
2
–VS
3
G = 30
+VS
5
OUT
100k⍀
FILTER
4
G=2
AD626
range of this amplifier is equal to 6 (+VS – 1 V) which provides a
+24 V CMR while operating from a +5 V supply. Fur thermore,
the AD626 features a CMR of 90 dB typ.
PRODUCT DESCRIPTION
The AD626 is a low cost, true single-supply differential amplifier
designed for amplifying and low-pass filtering small differential
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
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 between 10 and
100 can be easily configured with an external resistor. 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 temperature
range of –40°C to +85°C. The AD626 is available in two 8-lead
packages: a plastic mini-DIP and SOIC.
25
120
100
G = 10, 100
VS = +5V
80
G = 100
VS = ؎5V
60
40
G = 10
VS = ؎5V
20
1
10
100
1k
FREQUENCY – Hz
10k
100k
1M
Figure 1. Common-Mode Rejection vs. Frequency
INPUT COMMON-MODE RANGE – V
140
COMMON-MODE REJECTION – dB
8
1/6
APPLICATIONS
Current Sensing
Interface for Pressure Transducers, Position Indicators,
Strain Gages, and Other Low Level Signal Sources
0
0.1
200k⍀
1
20
؎VCM FOR SINGLE
AND DUAL SUPPLIES
15
10
؎VCM FOR DUAL
SUPPLIES ONLY
5
0
1
2
3
SUPPLY VOLTAGE – ؎V
4
5
Figure 2. Input Common-Mode Range vs. Supply
REV. D
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