MEMS accelerometer reduces power consumption

Analog Devices, Inc. (ADI) has developed a new three-axis MEMS accelerometer that improves power consumption by two times versus a previous generation device (ADXL362). The ADXL367 accelerometer consumes 0.88 µA at a 100-Hz output data rate and 180 nA when in motion-triggered wake-up mode. The device can be used in a range of health-care and industrial applications, including vital-signs monitoring, hearing aids, and motion-enabled metering devices.

MEMS accelerometer reduces power consumption

Click for a larger image. (Source: Analog Devices, Inc.)

To achieve low power consumption, the ADXL367 does not alias input signals by under sampling but instead samples the full bandwidth of the sensor at all data rates, said ADI. The device also offers improved noise performance (170 µg/√Hz) by over 30 percent compared with the previous generation. In addition, it extends field time, which maximizes battery life and reduces maintenance frequency and cost, said ADI.

The ADXL367 operates with supply voltages as low as 1.1 V (1.1 V to 3.6 V), which allows for single-cell battery operation without external boost converters, and delivers 200-nW motion detection in wakeup mode and 970 nW in measurement. The device includes a deep multimode output first in, first out (FIFO), a built-in micropower temperature sensor, an internal analog-to-digital converter (ADC) for synchronous conversion of an additional analog input, single-tap and double-tap detection, and a state machine to prevent a false triggering. It also offers provisions for external control of the sampling time and/or an external clock.

MEMS accelerometer reduces power consumption

ADI ADXL367 functional block diagram. Click for a larger image. (Source: Analog Devices, Inc.)

Digital features, such as single/double tap, free fall, and activity detection, reduce computation demand for the host microprocessor, and further improve system power consumption, said ADI.

The ADXL367, housed in a 2.2 × 2.3 × 0.87 mm package, is available now. The device is priced at $2.95 each per 1,000 quantity.

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