LIS3DH

Part: LIS3DH

Type: 3-axis Linear Accelerometer

Key Specs:

• Supply Voltage: 1.71 V to 3.6 V
• IO Supply: 1.8 V
• Ultra-low-power mode consumption: down to 2 μA
• Full Scale: ±2g/±4g/±8g/±16g
• Data Output: 16-bit
• Output Data Rates: 1 Hz to 5.3 kHz
• High Shock Survivability: 10000 g
• Operating Temperature Range: -40 °C to +85 °C

Features:

• Independent IO supply (1.8 V) and supply voltage compatible
• I2C/SPI digital output interface
• 2 independent programmable interrupt generators for free-fall and motion detection
• 6D/4D orientation detection
• Free-fall detection
• Motion detection
• Embedded temperature sensor
• Embedded self-test
• Embedded 32 levels of 16-bit data output FIFO
• ECOPACK®, RoHS and "Green" compliant
• Ultra-low-power operational modes

Applications:

• Motion activated functions
• Free-fall detection
• Click/double-click recognition
• Intelligent power saving for handheld devices
• Pedometers
• Display orientation
• Gaming and virtual reality input devices
• Impact recognition and logging
• Vibration monitoring and compensation

Package:

• LGA-16: small thin plastic land grid array package

• Wide supply voltage, 1.71 V to 3.6 V
• Independent IO supply (1.8 V) and supply voltage compatible
• Ultra-low-power mode consumption down to 2 μA
• 2g/±4g/8g/16g dynamically selectable full scale
• I 2C/SPI digital output interface
• 16-bit data output
• 2 independent programmable interrupt generators for free-fall and motion detection
• 6D/4D orientation detection
• Free-fall detection
• Motion detection
• Embedded temperature sensor
• Embedded self-test
• Embedded 32 levels of 16-bit data output FIFO
• 10000 g high shock survivability
• ECOPACK®, RoHS and "Green" compliant

• Motion activated functions

• Free-fall detection

• Click/double-click recognition

• Intelligent power saving for handheld devices

• Pedometers

• Display orientation

• Gaming and virtual reality input devices

• Impact recognition and logging

• Vibration monitoring and compensation

Description

The LIS3DH is an ultra-low-power highperformance three-axis linear accelerometer belonging to the "nano" family, with digital I2C/SPI serial interface standard output. The device features ultra-low-power operational modes that allow advanced power saving and smart embedded functions.

The LIS3DH has dynamically user-selectable full scales of 2g/±4g/8g/16g and is capable of measuring accelerations with output data rates from 1 Hz to 5.3 kHz. The self-test capability allows the user to check the functioning of the sensor in the final application. The device may be configured to generate interrupt signals using two independent inertial wake-up/free-fall events as well as by the position of the device itself. Thresholds and timing of interrupt generators are programmable by the end user on the fly. The LIS3DH has an integrated 32-level first-in, firstout (FIFO) buffer allowing the user to store data in order to limit intervention by the host processor. The LIS3DH is available in small thin plastic land grid array package (LGA) and is guaranteed to operate over an extended temperature range from -40 °C to +85 °C.

Table 1. Device summary

| Order codes | Temp.
range [C] | Package | Packaging | |-------------|---------------------|---------|---------------|--| | LIS3DHTR | -40 to +85 | LGA-16 | Tape and reel | Contents LIS3DH

1.1 Block diagram

Figure 1. Block diagram

1.2 Pin description

Figure 2. Pin connections

Table 2. Pin description

^1. SDO/SA0 pin is internally pulled up. Refer to Table 3 for the internal pull-up values (typ.).

Table 3. Internal pull-up values (typ.) for SDO/SA0 pin

2.1 Mechanical characteristics

Vdd = 2.5 V, T = 25 °C unless otherwise noted (a)

Table 4. Mechanical characteristics

| Symbol | Parameter | Test conditions | Min. | Typ. ⁽¹⁾ | Max. | Unit | |--------|-----------------------------------------------------------------|-------------------------------------------|------|---------------------|------|-------------------|--| | | | FS bit set to 00 | | ±2.0 | | FS I | (2) | FS bit set to 01 | | ±4.0 | | | Measurement range ⁽²⁾ | FS bit set to 10 | | ±8.0 | | | | FS bit set to 11 | | ±16.0 | | g | | | | FS bit set to 00;
High-resolution mode | | 1 | | | | FS bit set to 00;
Normal mode | | 4 | | m g /digit | | | | FS bit set to 00;
Low-power mode | | 16 | | | | FS bit set to 01;
High-resolution mode | | 2 | | m g /digit | | | Sensitivity | FS bit set to 01;
Normal mode | | 8 | | 0- | | FS bit set to 01;
Low-power mode | | 32 | | So | | FS bit set to 10;
High-resolution mode | | 4 | | | | FS bit set to 10;
Normal mode | | 16 | | | | FS bit set to 10;
Low-power mode | | 64 | | | | FS bit set to 11;
High-resolution mode | | 12 | | m g /digit | | | | FS bit set to 11;
Normal mode | | 48 | | | | FS bit set to 11;
Low-power mode | | 192 | | TCSo | Sensitivity change vs temperature | FS bit set to 00 | | 0.01 | | %/°C | | TyOff | Typical zero- g level offset accuracy ^(3),(4) | FS bit set to 00 | | ±40 | | m g | a. The product is factory calibrated at 2.5 V. The operational power supply range is from 1.71 V to 3.6 V.

577

Table 4. Mechanical characteristics

• 1. Typical specifications are not guaranteed.
• 1. Verified by wafer level test and measurement of initial offset and sensitivity.
• 1. Typical zero-g level offset value after MSL3 preconditioning.
• 1. Offset can be eliminated by enabling the built-in high-pass filter.
• 1. The sign of "Self-test output change" is defined by the ST bits in CTRL\_REG4 (23h), for all axes.
• 1. "Self-test output change" is defined as the absolute value of: OUTPUT[LSb](Self test enabled) - OUTPUT[LSb](Self test disabled). 1LSb = 4 mg at 10-bit representation, ±2 g full scale.
• 1. After enabling the self-test, correct data is obtained after two samples (low-power mode / normal mode) or after eight samples (high-resolution mode).

2.2 Temperature sensor characteristics

Vdd = 2.5 V, T = 25 °C unless otherwise noted (b)

Table 5. Temperature sensor characteristics

^1. Typical specifications are not guaranteed.

2.3 Electrical characteristics

Vdd = 2.5 V, T = 25 °C unless otherwise noted (c)

Table 6. Electrical characteristics

^1. Typical specification are not guaranteed.

^{2. 8-}bit resolution.

^2. It is possible to remove Vdd maintaining Vdd_IO without blocking the communication busses, in this condition the measurement chain is powered off.

^3. Refer to Table 25 for the ODR value and configuration.

b. The product is factory calibrated at 2.5 V. Temperature sensor operation is guaranteed in the range 2 V - 3.6 V.

c. The product is factory calibrated at 2.5 V. The operational power supply range is from 1.71 V to 3.6 V.

2.4 Communication interface characteristics

2.4.1 SPI - serial peripheral interface

Subject to general operating conditions for Vdd and Top.

Table 7. SPI slave timing values

| | | | Value (1) | |-------------|-------------------------|-----|-----------|------|--| | Symbol | Parameter | Min | Max | Unit | | tc(SPC) | SPI clock cycle | 100 | | ns | | fc(SPC) | SPI clock frequency | | 10 | MHz | | su(CS)
t | CS setup time | 5 | | th(CS) | CS hold time | 20 | | tsu(SI) | SDI input setup time | 5 | | th(SI) | SDI input hold time | 15 | | ns | | tv(SO) | SDO valid output time | | 50 | | th(SO) | SDO output hold time | 5 | | tdis(SO) | SDO output disable time | | 50 | ^1. Values are guaranteed at 10 MHz clock frequency for SPI with both 4 and 3 wires, based on characterization results, not tested in production.

Figure 3. SPI slave timing diagram

1. When no communication is ongoing, data on SDO is driven by internal pull-up resistors.

Note: Measurement points are done at 0.2·Vdd_IO and 0.8·Vdd_IO, for both input and output ports.

2.4.2 I2C - Inter IC control interface

Subject to general operating conditions for Vdd and top.

Table 8. I2C slave timing values

| | | I | 2C standard | I | 2C fast mode (1) | |-----------|---------------------------------------------------|-----|-------------|-----|------------------|------| | Symbol | Parameter | Min | Max | Min | Max | Unit | | f(SCL) | SCL clock frequency | 0 | 100 | 0 | 400 | kHz | | tw(SCLL) | SCL clock low time | 4.7 | | 1.3 | | tw(SCLH) | SCL clock high time | 4.0 | | 0.6 | | μs | | tsu(SDA) | SDA setup time | 250 | | 100 | | ns | | th(SDA) | SDA data hold time | 0 | 3.45 | 0 | 0.9 | μs | | th(ST) | START condition hold time | 4 | | 0.6 | | tsu(SR) | Repeated START condition setup time | 4.7 | | 0.6 | | tsu(SP) | STOP condition setup time | 4 | | 0.6 | | μs | | tw(SP:SR) | Bus free time between STOP and
START condition | 4.7 | | 1.3 | ^1. Data based on standard I2C protocol requirement, not tested in production.

SDA SCL tsu(SP) tw(SCLL) tsu(SDA) tsu(SR) th(ST) tw(SCLH) th(SDA) tw(SP:SR) START REPEATED START STOP START

Figure 4. I2C slave timing diagram

Note: Measurement points are done at 0.2·Vdd_IO and 0.8·Vdd_IO, for both ports.

2.5 Absolute maximum ratings

Stresses above those listed as "absolute maximum ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device under these conditions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.

Table 9. Absolute maximum ratings

Note: Supply voltage on any pin should never exceed 4.8 V

This device is sensitive to mechanical shock, improper handling can cause permanent damage to the part.

This device is sensitive to electrostatic discharge (ESD), improper handling can cause permanent damage to the part.

3 Terminology and functionality

3.1 Terminology

3.1.1 Sensitivity

Sensitivity describes the gain of the sensor and can be determined, for example, by applying 1 g acceleration to it. As the sensor can measure DC accelerations this can be done easily by pointing the axis of interest towards the center of the Earth, noting the output value, rotating the sensor by 180 degrees (pointing to the sky) and noting the output value again. By doing so, $\pm 1$ g acceleration is applied to the sensor. Subtracting the larger output value from the smaller one, and dividing the result by 2, leads to the actual sensitivity of the sensor. This value changes very little over temperature and also time. The sensitivity tolerance describes the range of sensitivities of a large population of sensors.

3.1.2 Zero-g level

The zero-g level offset (TyOff) describes the deviation of an actual output signal from the ideal output signal if no acceleration is present. A sensor in a steady state on a horizontal surface measures 0 g for the X-axis and 0 g for the Y-axis whereas the Z-axis measures 1 g. The output is ideally in the middle of the dynamic range of the sensor (content of OUT registers 00h, data expressed as 2's complement number). A deviation from ideal value in this case is called Zero-g offset. Offset is to some extent a result of stress to MEMS sensor and therefore the offset can slightly change after mounting the sensor onto a printed circuit board or exposing it to extensive mechanical stress. Offset changes little over temperature, see Table 4 "Zero-g level change vs. temperature" (TCOff). The zero-g level tolerance (TyOff) describes the standard deviation of the range of zero-g levels of a population of sensors.

Stresses above those listed as "absolute maximum ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device under these conditions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.

Table 9. Absolute maximum ratings

Note: Supply voltage on any pin should never exceed 4.8 V

This device is sensitive to mechanical shock, improper handling can cause permanent damage to the part.

This device is sensitive to electrostatic discharge (ESD), improper handling can cause permanent damage to the part.