current limit behavior. The inputs are protected even if no
power supply voltage is present.
OUTPUT VOLTAGE SENSE (SOL-16 package only)
The surface-mount version of the INA114 has a separate
output sense feedback connection (pin 12). Pin 12 must be
connected to the output terminal (pin 11) for proper opera-
tion. (This connection is made internally on the DIP version
of the INA114.)
The output sense connection can be used to sense the output
voltage directly at the load for best accuracy. Figure 5 shows
how to drive a load through series interconnection resis-
tance. Remotely located feedback paths may cause instabil-
ity. This can be generally be eliminated with a high
frequency feedback path through C
1
. Heavy loads or long
lines can be driven by connecting a buffer inside the feed-
back path (Figure 6).
V
CM
–
G • V
D
2
V+
Over-Voltage
Protection
V
D
2
INA114
A
1
25kΩ
25kΩ
25kΩ
G=1+
50kΩ
R
G
R
G
25kΩ
A
2
25kΩ
A
3
V
O
= G • V
D
V
D
2
Over-Voltage
Protection
V
CM
25kΩ
V
CM
+
G • V
D
2
V–
FIGURE 4. Voltage Swing of A
1
and A
2
.
Surface-mount package
version only.
–
Surface-mount package
version only.
–
V
IN
V
IN
R
G
V
IN
+
Output
Sense
INA114
Ref
C
1
1000pF
Output
Sense
R
G
INA114
Ref
180Ω
OPA633
I
L
: ±100mA
R
L
Load
+
V
IN
Equal resistance here preserves
good common-mode rejection.
FIGURE 5. Remote Load and Ground Sensing.
FIGURE 6. Buffered Output for Heavy Loads.
–
V
IN
+
V
IN
22.1kΩ
22.1kΩ
511Ω
INA114
Ref
V
O
Shield is driven at the
common-mode potential.
100Ω
OPA602
For G = 100
R
G
= 511Ω // 2(22.1kΩ)
effective R
G
= 505Ω
FIGURE 7. Shield Driver Circuit.
®
INA114
10
BURR-BROWN [ BURR-BROWN CORPORATION ]
