ADXL320JCP Analog Devices Inc, ADXL320JCP Datasheet - Page 13

• Manufacturer Part Number: ADXL320JCP
• Description: IC, 2 AXIS ACCELEROMETER, ± 5G, LFCSP-16
• Manufacturer: Analog Devices Inc
• Series: iMEMS®r

Specifications of ADXL320JCP

• No. Of Axes: 2
• Sensor Case Style: LFCSP
• No. Of Pins: 16
• Supply Voltage Range: 2.4V To 5.25V
• Operating Temperature Range: -20°C To +70°C
• Msl: MSL 1 - Unlimited
• Acceleration Range: ± 5g
• Axis: X, Y
• Sensitivity: 174mV/g
• Voltage - Supply: 2.4 V ~ 5.25 V
• Output Type: Analog
• Bandwidth: 1Hz ~ 500Hz Selectable
• Mounting Type: Surface Mount
• Package / Case: 16-LQFN, CSP Exposed Pad
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: ADXL320EB - BOARD EVAL FOR ADXL320
• Interface: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: Q2045089

Peak-to-peak noise values give the best estimate of the
uncertainty in a single measurement. Table 7 gives the typical
noise output of the ADXL320 for various C
Table 7. Filter Capacitor Selection (C
Bandwidth
(Hz)
10
50
100
500
USE WITH OPERATING VOLTAGES OTHER THAN 3 V
The ADXL320 is tested and specified at V
can be powered with V
Note that some performance parameters change as the supply
voltage is varied.
The ADXL320 output is ratiometric, so the output sensitivity
(or scale factor) varies proportionally to supply voltage. At V
5 V, the output sensitivity is typically 312 mV/g. At V
the output sensitivity is typically 135 mV/g.
The zero g bias output is also ratiometric, so the zero g output is
nominally equal to V
The output noise is not ratiometric but is absolute in volts;
therefore, the noise density decreases as the supply voltage
increases. This is because the scale factor (mV/g) increases
while the noise voltage remains constant. At V
density is typically 150 μg/√Hz, while at V
density is typically 300 μg/√Hz,
Self-test response in g is roughly proportional to the square of
the supply voltage. However, when ratiometricity of sensitivity
is factored in with supply voltage, the self-test response in volts
is roughly proportional to the cube of the supply voltage. For
example, at V
approximately 250 mV. At V
approximately 25 mV.
The supply current decreases as the supply voltage decreases.
Typical current consumption at V
current consumption at V
S
= 5 V, the self-test response for the ADXL320 is
C
(μF)
0.47
0.1
0.047
0.01
X
, C
S
/2 at all supply voltages.
S
Y
as low as 2.4 V or as high as 5.25 V.
S
= 2.4 V is 350 μA.
RMS Noise
(mg)
1.0
2.25
3.2
7.1
S
= 2.4 V, the self-test response is
S
= 5 V is 750 μA, and typical
X
, C
S
S
Y
Peak-to-Peak Noise
Estimate (mg)
6
13.5
18.9
42.8
= 3 V; however, it
X
= 2.4 V, the noise
)
and C
S
= 5 V, the noise
Y
values.
S
= 2.4 V,
Rev. 0 | Page 13 of 16
S
=
USE AS A DUAL-AXIS TILT SENSOR
Tilt measurement is one of the ADXL320’s most popular
applications. An accelerometer uses the force of gravity as an
input vector to determine the orientation of an object in space.
An accelerometer is most sensitive to tilt when its sensitive axis
is perpendicular to the force of gravity (that is, when it is
parallel to the earth’s surface). At this orientation, its sensitivity
to changes in tilt is highest. When the accelerometer is oriented
on axis to gravity (near its +1 g or −1 g reading), the change in
output acceleration per degree of tilt is negligible. When the
accelerometer is perpendicular to gravity, its output changes
nearly 17.5 mg per degree of tilt. At 45°, its output changes at
only 12.2 mg per degree of tilt, and resolution declines.
Converting Acceleration to Tilt
When the accelerometer is oriented so both its X-axis and
Y-axis are parallel to the earth’s surface, it can be used as a 2-
axis tilt sensor with both a roll axis and pitch axis. Once the
output signal from the accelerometer has been converted to an
acceleration that varies between −1 g and +1 g, the output tilt in
degrees is calculated as
Be sure to account for overranges. It is possible for the
accelerometers to output a signal greater than ±1 g due to
vibration, shock, or other accelerations.
PITCH = ASIN(A
ROLL = ASIN(A
Y
/1 g)
X
/1 g)
ADXL320