EVAL-ADXL330 AD [Analog Devices], EVAL-ADXL330 Datasheet - Page 13

• Manufacturer Part Number: EVAL-ADXL330
• Manufacturer: AD [Analog Devices]

The ADXL330 output is ratiometric, therefore, the output
sensitivity (or scale factor) varies proportionally to the
supply voltage. At V
typically 360 mV/g. At V
typically 195 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
X- and Y-axis noise density is typically 230 μg/√Hz, while at
V
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 −275 mV for the X-axis, +275 mV for the Y-axis,
and −100 mV for the Z-axis.
S
= 2 V, the X- and Y-axis noise density is typically 350 μg/√Hz.
S
= 3.6 V, the self-test response for the ADXL330 is
S
S
= 3.6 V, the output sensitivity is
/2 at all supply voltages.
S
= 2 V, the output sensitivity is
X
Y
Z
OUT
OUT
OUT
= 0g
= 0g
= 1g
TOP
S
Figure 32. Output Response vs. Orientation to Gravity
= 3.6 V, the
X
Y
Z
X
Y
Z
OUT
OUT
OUT
OUT
OUT
OUT
TOP
TOP
= 0g
= 1g
= 0g
= –1g
= 0g
= 0g
Rev. 0 | Page 13 of 16
TOP
X
Y
Z
X
Y
Z
OUT
OUT
OUT
OUT
OUT
OUT
At V
the X-axis, +60 mV for the Y-axis, and −25 mV for the Z-axis.
The supply current decreases as the supply voltage decreases.
Typical current consumption at V
typical current consumption at V
AXES OF ACCELERATION SENSITIVITY
Figure 31. Axes of Acceleration Sensitivity, Corresponding Output Voltage
= 0g
= 0g
= –1g
= 1g
= 0g
= 0g
S
= 2 V, the self-test response is approximately −60 mV for
A
Z
Increases When Accelerated Along the Sensitive Axis
GRAVITY
X
Y
Z
OUT
OUT
OUT
= –1g
= 0g
= 0g
A
Y
S
S
= 2 V is 200 μA.
= 3.6 V is 375 μA, and
ADXL330
A
X