Datasheet

For gain error, it depends on its input impedance and R
IN
.
IN
IN
R
GainError
2Z
−
=
×
Avoid additional gain error shift due to the effect of R
IN
.
For gain error, the MAX44284 is 0.15%. If the margin of
additional effect of R
IN
results in a gain error shift of less
than 0.02%, then:
IN
IN
0.02%
R 600
2Z
<=W
×
So R
IN
can be chosen ≤ 500Ω.
Output Filtering
The internal architecture of the MAX44284 suppresses the
DC offset, 1/f noise, and accumulates at higher frequen-
cies so that they can be filtered out. Hence, minute AC
disturbances can be observed at 10kHz and 20kHz. It is
recommended to add an output filter after the MAX44284
to avoid noise and unwanted frequency disturbances at
the output with 5kHz -3dB f
c
(see Figure 3).
(Suggested values of C and R : 2.2nF and 1.8kΩ, respec-
tively.)
Bidirectional Application
Battery-powered systems may require a precise bidirec-
tional current-sense amplifier to accurately monitor the
battery’s charge and discharge currents. Measurements
of the two separate outputs with respect to GND yield an
accurate measure of the charge and discharge currents
respectively (Figure 4).
Figure 3. Filtering
Figure 4. Bidirectional Application
RS-
R
RS+
R
IN
R
IN
C
IN2
R
SENSE
V
BATT
OUT
MAX44284
LOAD
C
C
IN
C
IN
TO WALL-CUBE
CHARGER
RS+
OUT
RS- RS+
OUT
RS-
R
SENSE
I
LOAD
LOAD
µC
V
DD
= 3.3V
V
BATT
UP TO 36V
MAX44284 MAX44284
ADC
ADC
MAX44284 36V, Input Common-Mode, High-Precision,
Low-Power Current-Sense Amplier
www.maximintegrated.com
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