INA101SG BURR-BROWN [Burr-Brown Corporation], INA101SG Datasheet - Page 6

• Manufacturer Part Number: INA101SG
• Description: High Accuracy INSTRUMENTATION AMPLIFIER
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

OFFSET TRIMMING
The INA101 is laser trimmed for low offset voltage and
drift. Most applications require no external offset adjust-
ment. Figure 2 shows connection of an optional potentio-
meter connected to the Offset Adjust pins for trimming the
input offset voltage. (Pin numbers shown are for the DIP
package.) Use this adjustment to null the offset voltage in
high gain (G
Do not use this adjustment to null offset produced by the
source or other system offset since this will increase the
offset voltage drift by 0.3 V/ C per 100 V of adjusted
offset.
Offset of the output amplifier usually dominates when the
INA101 is used in unity gain (G = 1). The output offset
FIGURE 2. Optional Trimming of Input and Output Offset Voltage.
FIGURE 1. Basic Connections.
G = 1 +
Do not use to null source or system
40k
Input Offset Adjustment
R
R
G
E
E
G
offset (see text).
2
1
®
G = 1 +
100) with both inputs connected to ground.
INA101
10
11
12
3
4
5
40k
R
G
E
E
2
1
R
G
10
1
4
5
+15V
2
100k
Tantalum
–15V
6
A
A
1µF
1
2
13
20k
20k
+
+15V
7
A
A
1
2
+15V
9
Output
Output
Connection
–15V
2
10k
10k
A
A
No
1
2
6
20k
20k
3
DIP PACKAGE
Tantalum
6
1µF
is for DIP packages.
INA101
voltage can be adjusted with the optional trim circuit con-
nected to the Common pin as shown in Figure 2. The voltage
applied to Common terminal is summed with the output.
Low impedance must be maintained at this node to assure
good common-mode rejection. The op amp connected as a
buffer provides low impedance.
THERMAL EFFECTS ON OFFSET VOLTAGE
To achieve lowest offset voltage and drift, prevent air
currents from circulating near the INA101. Rapid changes in
temperature will produce a thermocouple effect on the
package leads that will degrade offset voltage and drift. A
shield or cover that prevents air currents from flowing near
the INA101 will assure best performance.
+
A
Pinout shown
10k
10k
3
10k
10k
TO-100 PACKAGE
14
1
INA101
Common
+15V
–15V
A
10k
10k
3
100k
V
O
= G (E
1M
1
7
8
– E
Output
2
) +V
1k
V
OPA177
COM
O
= G (E
Output Offset
Adjustment
1
– E
V
COM
2
)
Approximately
±15mV Range