INA106KU Burr-Brown Corporation, INA106KU Datasheet - Page 6

• Manufacturer Part Number: INA106KU
• Description: Precision Gain = 10 DIFFERENTIAL AMPLIFIER
• Manufacturer: Burr-Brown Corporation

FIGURE 3. Difference Amplifier with Gain and CMR Adjust.
FIGURE 4. Precision G = –10 Inverting Amplifier.
FIGURE 5. Voltage Follower with Input Protection.
This circuit follows an 11/1 divider with a gain of 11 for an overall gain of unity.
With an 11/1 divider, the input signal can exceed 100V without damage.
V
V
1
2
Safe Input
10
10
V
2
±100V
V
IN
®
2
3
To eliminate adjustment interactions,
2
first adjust gain with V
Gain Error = 0.01% maximum
Nonlinearity = 0.001% maximum
Gain Drift = 2.ppm/°C
2
1
INA106
10k
10k
10k
10k
100k
10k
3
R
R
1
4
INA106
INA106
INA106
1
100k
3
10k
100k
100k
100k
2
R
grounded.
3
100k
R
2
5
6
1
5
6
V
5
6
O
200
200
= –10V
V
O
V
= V
O
V
O
IN
2
Gain
Adjust
CMR
Adjust
E
0
6
FIGURE 6. Precision Instrumentation Amplifier.
FIGURE 8. Precision G = 11 Buffer.
FIGURE 7. Precision Summing Amplifier.
To make a high performance high gain instrumentation amplifier, the INA106
can be combined with state-of-the-art op amps. For low source impedance
applications, OPA37s will give the best noise, offset, and temperature drift. At
source impedances above about 10k , the bias current noise of the OPA37
reacting with input impedance degrades noise. For these applications, use an
OPA111 or a dual OPA2111 FET input op amp for lower noise. For an
electrometer grade IA, use the OPA128—see table below.
Using the INA106 for the difference amplifier also extends the input common-
mode range of the instrumentation amplifier to 10V. A conventional IA with
a unity-gain difference amplifier has an input common-mode range limited to
needs 5V at the input for 10V at the output, allowing only 5V additional for
common-mode.
–In
+In
E
E
A
OPA37A
OPA111B
OPA128LM
5V for an output swing of 10V. This is because a unity-gain difference amp
1
2
1
, A
V
2
IN
R
1
V
V
1
3
A
A
R
R
1
2
2
2
2
1
3
50.5
202
202
( )
R
1
3
1
100k
10k
10k
(k )
2.5
R
R
R
R
10
10
1
4
3
2
2
3
GAIN
INA106
(V/V)
1000
1000
1000
E
INA106
0
= 10(1 + 2R
CMRR
100k
(dB)
128
110
118
R
2
INA106
2
I
40000
b
0.075
/R
(pA)
1
1
5
6
) (E
V
2
5
6
0
0.01% maximum
2
= V
Gain Error =
– E
V
NOISE AT 1kHz
V
O
1
0
= 11V
1
+ 10 V
)
(nV/ Hz)
V
5
6
1
O
10
38
4
IN
3
Output
E
0