Datasheet

INA138, INA168
8
SBOS122C
www.ti.com
FIGURE 6. Bipolar Current Measurement Using Differential Input of A/D Converter.
FIGURE 7. Multiplexed Measurement Using Logic Signal for Power.
INA168
INA168
Other INA168s
––
––
IN4148
REF
V+
V+
R
L
Serial
I/O
ADS7870
Clock
Divider
Oscillator
BUF
OUT
BUF
IN
REF
OUT
12-Bit
A/D
Converter
BUF
MUX
Digital
I/O
PGIA
+5V
Digital I/O on the ADS7870 provides power to select
the desired INA168. Diodes prevent output current of
the
on INA168 from flowing into the off INA168.
REF
Serial
I/O
ADS7870
Clock
Divider
Oscillator
BUF
OUT
BUF
IN
REF
OUT
12-Bit
A/D
Converter
BUF
MUX
Digital
I/O
PGIA
+5V
1
2
+5V
5
4
3
1
2
+5V
5
4
3
R
S
R
L
25kΩ
R
L
25kΩ
V+
INA138INA138
A/D converter programmed for differential input.
Depending on polarity of current, one INA138 provides
an output voltage, the output of the other is zero.