ADXL36±
Data Sheet
Current consumption varies somewhat with output data rate as
shown in Figure 30, remaining below 5.0 µA over the entire
range of data rates and operating voltages.
6
POWER/NOISE TRADEOFF
The ADXL362 offers a few options for decreasing noise at the
expense of only a small increase in current consumption.
V
V
V
V
V
= 1.6V
= 2.0V
= 2.5V
= 3.0V
= 3.5V
S
S
S
S
S
The noise performance of the ADXL362 in normal operation,
typically 7 LSB rms at 100 Hz bandwidth, is adequate for most
applications, depending upon bandwidth and the desired reso-
lution. For cases where lower noise is needed, the ADXL362
provides two lower noise operating modes that trade reduced
noise for a somewhat higher current consumption.
5
4
3
2
1
0
Table 7 lists the current consumption and noise densities obtained
for normal operation and the two lower noise modes at a typical
2.0 V supply.
Table 7. Noise and Current Consumption: Normal Operation,
Low Noise Mode, and Ultralow Noise Mode @ VS = 2.0 V,
ODR = 100 Hz
0
100
200
300
400
OUTPUT DATA RATE (Hz)
Noise
(µg/√Hz)
Typical
Current
Consumption (µA)
Typical
Figure 30. Current Consumption vs. Output Data Rate at Several
Supply Voltages
Mode
Antialiasing
Normal Operation
Low Noise
Ultralow Noise
550
400
250
1.8
3.3
13
The analog-to-digital converter (ADC) of the ADXL362 samples
at the (user selected) output data rate. In the absence of anti-
aliasing filtering, it aliases any input signals whose frequency is
more than half the data rate. To mitigate this, a two-pole low-
pass filter is provided at the input of the ADC.
Operating the ADXL362 at a higher supply voltage also decreases
noise. Table 8 lists the current consumption and noise densities
obtained for normal operation and the two lower noise modes
at the highest recommended supply, 3.3 V.
The user can set this antialiasing filter to a bandwidth that is at
½ the data rate or ¼ the data rate. Setting the antialiasing filter
pole to ½ of the output data rate provides less aggressive
antialiasing filtering, but maximizes bandwidth and is adequate
for most applications. Setting the pole to ¼ of the data rate
reduces bandwidth for a given data rate, but provides more
aggressive antialiasing.
Table 8. Noise and Current Consumption: Normal Operation,
Low Noise Mode, and Ultralow Noise Mode @ VS = 3.3 V,
ODR = 100 Hz
Noise
(µg/√Hz)
Typical
Current
Consumption (µA)
Typical
Mode
The antialiasing filter of the ADXL362 defaults to the more
conservative setting, where bandwidth is set to one-fourth the
output data rate.
Normal Operation
Low Noise
Ultralow Noise
380
280
175
2.7
4.5
15
Rev. B | Page 14 of 44
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