ALLGEMEINE BESCHREIBUNG

The digital output ADXL359 is a low noise density, low 0 g offset drift, low power, 3-axis microelectromechanical system (MEMS) accelerometer with selectable measurement ranges. The ADXL359 supports the ±10 g, ±20 g, and ±40 g ranges.
The ADXL359 offers industry leading noise, minimal offset drift over temperature, and long-term stability, enabling precision applications with minimal calibration.
The low drift, low noise, and low power ADXL359 enables accurate tilt measurement in an environment with high vibration, such as airborne inertial measurement units (IMUs). The low noise over higher frequencies is ideal for wireless condition monitoring.
The ADXL359 multifunction pin names may be referenced only by their relevant function for either the serial peripheral interface (SPI) or limited I²C interface.

 

FEATURES

► 0 g offset vs. temperature (all axes): 0.45 mg/°C typical
► Ultralow noise density (all axes): 80 µg/√Hz
► Low power, VSUPPLY (LDO enabled)
► In measurement mode: 200 µA
► In standby mode: 21 µA
► Digital output features
► Digital SPI and limited I2C interfaces supported
► 20-bit ADC
► Data interpolation routine for synchronous sampling
► Programmable high-pass and low-pass digital filters
► Integrated temperature sensor
► Voltage range options
► VSUPPLY with internal regulators: 2.25 V to 3.6 V
► V1P8ANA, V1P8DIG with internal LDO regulator bypassed: 1.8 V typical ± 10%
► Operating temperature range: −40°C to +125°C
► 14-terminal, 4 mm × 4 mm × 1.04 mm, LGA package

 

ANWENDUNGEN

► IMUs and altitude and heading reference systems (AHRSs)
► Platform stabilization systems
► Vibration sensing
► Structural health monitoring
► Tilt sensing
► Robotics
► Condition monitoring

 

ABSOLUTE HÖCHSTWERTE

Stresses at or above those listed under Absolute Maximum Ratings may cause permanent damage to the product. This is a stress rating only; functional operation of the product at these or any other conditions above those indicated in the operational section of this specification is not implied. Operation beyond the maximum operating conditions for extended periods may affect product reliability.

 

WÄRMEBESTÄNDIGKEIT

Thermal performance is directly linked to printed circuit board (PCB) design and operating environment. Careful attention to PCB thermal design is required.
θJA is the natural convection junction to ambient thermal resistance measured in a one cubic foot sealed enclosure. ψJB is the junction to board thermal resistance.

 

ARBEITSTHEORIE

The ADXL359 is a complete 3-axis, ultralow noise and ultrastable offset MEMS accelerometer with outputs ratiometric to the analog 1.8 V supply, V1P8ANA. The ADXL359 includes three high resolution ADCs that use the analog 1.8 V supply as a reference to provide digital outputs insensitive to the supply voltage. The ADXL359 is programmable for ±10 g, ±20 g, and ±40 g full scale. The ADXL359 offers both SPI and I²C communications ports.
The micromachined, sensing elements are fully differential, comprising the lateral x-axis and y-axis sensors and the vertical, teeter totter z-axis sensors. The x-axis and y-axis sensors and the z-axis sensors go through separate signal paths that minimize offset drift and noise. The signal path is fully differential.
The ADXL359 includes antialias filters before and after the high resolution Σ-Δ ADC. User-selectable output data rates and filter corners are provided. The temperature sensor is digitized with a 12-bit successive approximation register (SAR) ADC.

 

OVERRANGE PROTECTION

To avoid electrostatic capture of the proof mass when the accelerometer is subject to input acceleration beyond its full-scale range, all sensor drive clocks turn off for 0.5 ms. In the ±10 g range setting, the overrange protection activates for input signals beyond approximately ±40 g (±25%), and for the ±20 g and ±40 g range settings, the threshold corresponds to about ±80 g (±25%).

 

SELF TEST

The ADXL359 incorporates a self test feature that effectively tests the mechanical and electronic system. Enabling self test stimulates the sensor electrostatically to produce an output corresponding to the test signal applied as well as the mechanical force exerted. Only the z-axis response is specified to validate the device functionality.