LSM320HAY30 Datasheet, PDF (18/42 Pages) STMicroelectronics – MEMS motion sensor module: 3D digital accelerometer and 2D pitch and yaw analog gyroscope

Application hints
LSM320HAY30
The device core is supplied through the Vdd line. Power supply decoupling capacitors
(C1=100 nF ceramic, C2=10 µF aluminum) should be placed as near as possible to the
supply pin of the device (common design practice).
All voltage and ground supplies must be present at the same time to obtain proper behavior
of the IC (refer to Figure 3).
5.1
Linear acceleration sensing
The functionality of the device and the measured acceleration data is selectable and
accessible through the SPI/I²C interface.
The functions, the threshold and the timing of the two interrupt pins (INT 1 and INT 2) can be
completely programmed by the user though the SPI/I²C interface.
5.2
Angular rate sensing
The LSM320HAY30 allows band limitation of the output rate response through the use of an
external low-pass filter (recommended) and/or high-pass filter (optional) in addition to the
embedded low-pass filter (f_t = 140 Hz).
4xOUTX and 4xOUTZ are, respectively, OUTX and OUTZ amplified outputs lines, internally
buffered to ensure low output impedance.
If external filtering is not applied, it is mandatory to short-circuit pad 18 to pad 19 and pad 23
to pad 24, respectively, when amplified outputs are used.
When only a non-amplified output is used (OUTX/OUTZ), it is recommended to set pin 19
and 23 to a fixed reference voltage (Vref).
The LSM320HAY30 IC includes a PLL (phase locked loop) circuit to synchronize driving and
sensing interfaces. Capacitors and resistors must be added at the FILTVDD and VCONT
pins (as shown in Figure 3) to implement a second-order low-pass filter.
Figure 4. Angular rate output response vs. rotation
Z
1
Z
+ Ω_z
1
Y
Steady state position:
4xOUTX = 4xOUTZ = 1.5V
OUTX = OUTZ = 1.5V
X
+ Ω_x
Positive rotations as indicated by the arrows
increase output value over Zero rate level:
+300°/sec --> 4xOUTX, 4xOUTZ = 1.5V + SoA*300 = 2.5V
+300°/sec --> OUTX, OUTZ = 1.5V + So*300 = 1.75V
AM06042v1
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Doc ID 16917 Rev 1