STEVAL-IFS001V1 STMicroelectronics, STEVAL-IFS001V1 Datasheet - Page 14

• Manufacturer Part Number: STEVAL-IFS001V1
• Description: EVAL BOARD 3AXIS MEMS ACCELLRMTR
• Manufacturer: STMicroelectronics
• Series: MEMSr

Specifications of STEVAL-IFS001V1

• Design Resources: STEVAL-IFS001V1 Gerber Files STEVAL-IFS001V1 Schematic STEVAL-IFS001V1 Bill of Material
• Sensor Type: Accelerometer, 3 Axis
• Sensing Range: ±2g, 6g
• Interface: I²C, SPI
• Sensitivity: 1024 LSb/g
• Voltage - Supply: 2.16 V ~ 3.6 V
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: LIS3LV02DQ
• Processor To Be Evaluated: LIS3LV02DQ
• Interface Type: USB
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 497-5069

3 Functionality
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3.1
3.2
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Functionality
The LIS3LV02DQ is a high performance, low-power, digital output 3-axis linear accelerometer
packaged in a QFN package. The complete device includes a sensing element and an IC
interface able to take the information from the sensing element and to provide a signal to the
external world through an I
Sensing element
A proprietary process is used to create a surface micro-machined accelerometer. The
technology allows to carry out suspended silicon structures which are attached to the substrate
in a few points called anchors and are free to move in the direction of the sensed acceleration.
To be compatible with the traditional packaging techniques a cap is placed on top of the
sensing element to avoid blocking the moving parts during the moulding phase of the plastic
encapsulation.
When an acceleration is applied to the sensor the proof mass displaces from its nominal
position, causing an imbalance in the capacitive half-bridge. This imbalance is measured using
charge integration in response to a voltage pulse applied to the sense capacitor.
At steady state the nominal value of the capacitors are few pF and when an acceleration is
applied the maximum variation of the capacitive load is up to 100fF.
IC Interface
The complete measurement chain is composed by a low-noise capacitive amplifier which
converts into an analog voltage the capacitive unbalancing of the MEMS sensor and by three
Σ∆ analog-to-digital converters, one for each axis, that translate the produced signal into a
digital bitstream.
The Σ∆ converters are
frequency components of the quantization noise and provide low rate and high resolution digital
words.
The charge amplifier and the Σ∆ converters are operated respectively at 61.5 kHz and 20.5
kHz.
The data rate at the output of the reconstruction depends on the user selected Decimation
Factor (DF) and spans from 40 Hz to 2560 Hz.
The acceleration data may be accessed through an I
particularly suitable for direct interfacing with a microcontroller.
The LIS3LV02DQ features a Data-Ready signal (RDY) which indicates when a new set of
measured acceleration data is available thus simplifying data synchronization in digital system
employing the device itself.
The LIS3LV02DQ may also be configured to generate an inertial Wake-Up, Direction Detection
and Free-Fall interrupt signal accordingly to a programmed acceleration event along the
enabled axes.
coupled with dedicated reconstruction filters which remove the high
2
C/SPI serial interface.
CD00047926
2
C/SPI interface thus making the device
LIS3LV02DQ