ADXL367 Digital Output MEMS Accelerometer

ADI's ADXL367 ultralow power, 3-axis microelectromechanical systems (MEMS) accelerometer consumes just 0.89 μA at a 100 Hz output data rate and 180 nA when in motion-triggered wake-up mode. Unlike accelerometers using power duty cycling to achieve low power consumption, the ADXL367 does not alias input signals by undersampling but by sampling the full bandwidth of the sensor at all data rates.

The ADXL367 always provides 14-bit output resolution. Eight-bit formatted data is offered for more efficient single-byte transfers when a lower resolution is sufficient. Twelve-bit formatted data is provided for ADXL362 design compatibility. Measurement ranges of ±2 g, ±4 g, and ±8 g are available with a resolution of 0.25 mg/LSB in the ±2 g range.

In addition to ultralow power consumption, the ADXL367 has many features to enable true system-level power reduction. It includes deep multimode output first in, first out (FIFO), built-in micropower temperature sensor, internal analog-to-digital converter (ADC) for synchronous conversion of additional analog input with interrupt capability, single- and double-tap detection operating at any output data rate with only an added 35 nA of current, and a state machine to prevent false triggering. Additionally, the ADXL367 has provisions for external control of the sampling time, an external clock, or both.

The ADXL367 is available in a 2.2 mm x 2.3 mm x 0.87 mm package and operates on a wide 1.1 V to 3.6 V supply range that can interface to a host operating on a separate supply voltage if necessary.

The EVAL-ADXL367Z simple breakout board enables easy connection of an ADXL367 into an existing system. Due to its small size, the EVAL-ADXL367Z has minimal effect on the system’s performance and the accelerometer, making it ideal for evaluation of the ADXL367 in an existing system. Note that communication with the ADXL367 must be performed digitally via SPI or I²C. No processor is included with the EVAL-ADXL367Z; firmware must be supplied externally by the user. For evaluation boards with a processor, use the EVAL-ADXL367-SDP.

The EVAL-ADXL367-SDP easy-to-use evaluation system allows a quick start on testing and evaluating the ADXL367 accelerometer. The system consists of a main board (EVAL-SDP-CB1Z evaluation platform), an interface board (EVAL-SDP-INTER4-Z), and a satellite board (EVAL-ADXL367Z breakout board).

The EVAL-SDP-CB1Z board, also called “SDP-B,” connects directly to a PC via USB cable, with the USB connection providing both communications and power to the board. The SDP-B is connected to the interface board (EVAL-SDP-INTER4-Z), which provides the signal conditioning and electrical connections to communicate with the satellite board (EVAL-ADXL367Z) through a cable. This cable allows the satellite to be easily manipulated for testing or separately placed into an environmental chamber for temperature or humidity testing. Separating the boards mitigates the corruption of data due to the temperature and humidity effects of other components.