INA103_07 BURR-BROWN [Burr-Brown Corporation], INA103_07 Datasheet - Page 11

• Manufacturer Part Number: INA103_07
• Description: Low Noise, Low Distortion INSTRUMENTATION AMPLIFIER
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

FIGURE 9. INA103 Overload Condition Performance.
FIGURE 10. Optional Circuit for Externally Trimming CMR.
FIGURE 7. Gain Adjustment of Output Stage.
A common problem with many IC op amps and instrumentation amplifiers is shown in (a). Here, the amplifier’s input is driven beyond its linear common-mode
range, forcing the output of the amplifier into the supply rails. The output then “folds back”, i.e., a more positive input voltage now causes the output of the amplifier
to go negative. The INA103 has protection circuitry to prevent fold-back, and as shown in (b), limits cleanly.
Output Stage Gain =
(R
V
2
IN
|| 12k) + R
(R
V
16
15
13
14
IN
6
2
1
2
|| 12k)
16
15
13
14
6
2
1
1
(a) AD625 G = 1, V
+ R
INA103
3
+0.2% Gain Error.
approximately
INA103
Introduces
OUTPUT STAGE R
Gain = 1V/V
GAIN
IN
(0dB)
10
2
5
= 15V, R
20
11
7
10
11
7
10
L
10
= 600
1
(k )
1.2k
1.2k
and R
CMR
Trim
R
R
1k
2
3
R
1
3
632
273
2.4k
( )
R
2
V
OUT
11
FIGURE 11. Increasing Output Circuit Drive.
FIGURE 8. Use of External Resistors for Gain Set.
V
IN
R
V
G
IN
NOTE: AD625 equivalent pinout.
R
F
R
> 10k can increase noise and reduce bandwidth—see text.
16
15
13
14
G
6
2
1
(b) INA103 G = 1, V
16
15
13
14
6
2
1
INA103
R
R
Buffer inside feedback loop
F
F
INA103
IN
11
= 15V, R
7
INA103
10
12
5
MJ15012
MJ15011
L
100
= 600
G = 1+
11 10
7
V+
V–
2R
R
(To headphone
or speaker)
G
F
V
OUT
V
OUT
®