ad626 Analog Devices, Inc., ad626 Datasheet - Page 11

• Manufacturer Part Number: ad626
• Description: Low Cost, Single Supply Differential Amplifier
• Manufacturer: Analog Devices, Inc.

CURRENT OUT
CURRENT SENSOR INTERFACE
A typical current sensing application, making use of the large
common-mode range of the AD626, is shown in Figure 9. The
cur rent being measured is sensed across resistor R
R
average differential voltage across this resistor is typically 100 mV.
To produce a full-scale output of +4 V, a gain of 40 is used adjust-
able by ±20% to absorb the tolerance in the sense re sis tor. Note
that there is suffi cient headroom to allow at least a 10% over range
(to +4.4 V).
REV. D
CURRENT IN
S
should be less than 1 k and should be selected so that the
LOW-PASS
OPTIONAL
CURRENT
SENSOR
FILTER
–V
0.1 F
S
CF
Figure 9. Current Sensor Interface
R
S
1
2
3
4
–IN
ANALOG
GND
FILTER
–V
S
AD626
200k
100k
G = 30
1/6
200k
G = 2
G = 100
OUT
+IN
+V
S
8
7
6
5
S
. The value of
R
H
0.1 F
OUTPUT
+V
R
G
S
–11–
BRIDGE APPLICATION
Figure 10 shows the AD626 in a typical bridge application. Here,
the AD626 is set to operate at a gain of 100, using dual-sup ply
voltages and offering the option of low-pass fi ltering.
LOW-PASS
OPTIONAL
FILTER
–5V
+V
0.1 F
S
CF
Figure 10. A Typical Bridge Application
2
3
4
1
–IN
ANALOG
GND
–V
FILTER
S
AD626
200k
100k
G = 30
1/6
200k
G = 2
G = 100
OUT
+IN
+V
S
8
7
6
5
AD626
0.1 F
OUTPUT
+5V