max9934faua Maxim Integrated Products, Inc., max9934faua Datasheet - Page 14

• Manufacturer Part Number: max9934faua
• Description: High-precision, Low-voltage, Current-sense Amplifier With Current Output And Chip Select For Multiplexing
• Manufacturer: Maxim Integrated Products, Inc.

High-Precision, Low-Voltage, Current-Sense Amplifier
with Current Output and Chip Select for Multiplexing
A MAX9934 can be deselected by either forcing V
low as shown in Figures 4 and 5, or by making V
0V as shown in Figure 6. In all these conditions, the
MAX9934 maintains a high-impedance output with
0.1nA (typ) leakage current. In this state, OUT can rise
above V
can be used to power different MAX9934 devices that
are multiplexed on the same OUT bus. Multiplexing by
forcing the MAX9934 to be powered down (V
reduces its supply current to zero to help extend bat-
tery life in portable applications.
Figure 6. Multiplexed Amplifiers with Power Saving
14
______________________________________________________________________________________
CC
if necessary. Thus, different supply voltages
V
V
V
IN1
IN2
IN3
-0.1V ≤ V
-0.1V ≤ V
-0.1V ≤ V
CM
CM
CM
≤ 5.5V
≤ 5.5V
≤ 5.5V
R
R
R
I
I
SENSE
I
SENSE
LOAD1
SENSE
LOAD2
LOAD3
CC
= 0V)
CC
MAX9934
MAX9934
MAX9934
CS
=
V
V
V
CC
CC
CC
= 3.3V
= 3.3V
= 3.3V
In the current-sense application, the monitored load
current (I
across a current-sense resistor (R
MAX9934 sources or sinks an output current that is pro-
portional to V
rent is provided to an output resistor (R
an output voltage across R
the sensed load current.
1/4 MAX4737
1/4 MAX4737
1/4 MAX4737
0.1µF
0.1µF
CS
0.1µF
CS
CS
10kΩ
R
OUT3
OUT1
OUT2
OUT
LOAD
SENSE
) develops a sense voltage (V
(OPTIONAL)
Choosing R
. Finally, the MAX9934 output cur-
CS1
CS2
CS3
MICROCONTROLLER
ADC
OUT
that is proportional to
SENSE
OUT
SENSE
and R
) to develop
SENSE
). The
OUT
)