Datasheet

INA139, INA169
8
SBOS181D
www.ti.com
FIGURE 6. Bipolar Current Measurement Using a Differential Input of the A/D Converter.
FIGURE 7. Multiplexed Measurement Using Logic Signal for Power.
INA169
INA169
Other INA169s
––
––
1N4148
Digital I/O on the ADS7870 provides power to
select the desired INA169. Diodes prevent
output current of an
on INA169 from flowing
into an
off INA169.
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
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+
INA139INA139
The A/D converter is programmed for differential input.
Depending on the polarity of the current, one INA139 provides
an output voltage whereas the output of the other is zero.