Micropower 3-Sensor Combination Including Acceleration and Temperature

Home healthcare devices Wireless sensors Motion enabled metering devices

Accelerometer, temperature sensor, and provision for 3rd analog sensor input All sensors sampled synchronously Up to 400 Hz output data rate (ODR) Samples can be synchronized to external trigger Ultralow power 1.95 µA at 100 Hz ODR, 2.0 V supply, all sensors on 270 nA at 6 Hz motion activated wake-up mode 10 nA standby current 12-bit resolution for all sensors Acceleration scale factor down to 1 mg/LSB Temperature scale factor 0.065°C/LSB Built-in features for motion-based system-level power savings Adjustable threshold sleep/wake modes for motion activation Autonomous interrupt processing, without need for microcontroller intervention, to allow the rest of the system to be turned off completely Deep embedded FIFO minimizes host processor load Awake state output enables implementation of standalone, motion activated switch See datasheet for additional features

The ADXL363 is an ultralow power, three-sensor combination consisting of a 3-axis MEMS accelerometer, a temperature sensor, and an ADC input for synchronous conversion of an external signal. The entire system consumes less than 2 µA at a 100 Hz output data rate and 270 nA when in motion triggered wake-up mode.

The ADXL363 communicates via a serial port interface (SPI) and always provides 12-bit output resolution for all three sensors.

The ADXL363 accelerometer provides selectable measurement ranges of ±2g, ±4 g, and ±8 g, with a resolution of 1 mg/LSB on the ±2 g range. Unlike accelerometers that use power duty cycling to achieve low power consumption, the ADXL363 does not alias input signals by undersampling; it samples the full bandwidth of the sensor at all data rates.

The ADXL363 temperature sensor operates with a scale factor of 0.065°C (typical). Acceleration and temperature data can be stored in a 512-sample multimode FIFO buffer, allowing up to 13 sec of data to be stored.

In addition to the accelerometer and temperature sensor, the ADXL363 also provides access to an internal ADC for synchronous conversion of an additional analog input.

The ADXL363 operates on a wide 1.6 V to 3.5 V supply range, and can interface, if necessary, to a host operating on a separate, lower supply voltage. The ADXL363 is available in a 3 mm × 3.25 mm × 1.06 mm package.