New pressure sensor bolsters accuracy for altitude tracking

Article By : Majeed Ahmad

The capacitive barometric pressure sensor delivers an entirely new level of accuracy to detect an altitude change of just a few centimeters.

There is a new benchmark in barometric pressure sensors, according to Bosch Sensortec, which claims that its new sensing device can measure a barometric pressure fluctuation that’s equivalent to one-thousandth of the weight of a mosquito (7.6 μg).

The company’s CEO Stefan Finkbeiner says that the BMP581 barometric pressure sensor delivers an entirely new level of accuracy to detect an altitude change of just a few centimeters. “That enables it to monitor movement in fitness applications down to the level of individual pull-ups or push-ups.”

Figure 1 BMP581’s extreme accuracy makes it suitable for altitude tracking in fitness tracking, fall detection, indoor localization, and navigation. Source: Bosch Sensortec

BMP581—the first capacitive barometric pressure sensor from Bosch Sensortec—can provide highly accurate location information for indoor localization, navigation, and floor detection to provide key data for emergency call requirements (E-911). Moreover, it can improve the flight stability and landing accuracy in drones and help detect water levels in household appliances to avoid flooding.

Technical details

The new pressure sensor provides a relative accuracy of +/-0.06 hPa and typical absolute accuracy of +/-0.3 hPa; full accuracy is available over a wide measurement range from 300 hPa to 1100 hPa. Next, it features a temperature coefficient offset (TCO) of just +/-0.5 Pa/K and low RMS noise of 0.08 Pa @ 1000 hPa (typical).

Then there is the typical current consumption of just 1.3 μA at 1Hz while the deep standby mode draws only 0.5 μA. That substantially extends the battery life. Compared to the previous Bosch barometric pressure sensor BMP390, the new sensor draws 85% less current and 80% lower noise, while TCO is reduced by 33%.

Figure 2 Low noise and power consumption make BMP581 a good fit in wearables, hearables, and Internet of Things (IoT) devices. Source: Bosch Sensortec

BMP581, available in a compact 10-pin LGA package shielded by a metal cover, measures 2.0 x 2.0 x 0.75 mm3 and can be integrated using I2C, I3C, and 3-wire/4-wire SPI interfaces.

This article was originally published on EDN.

Majeed Ahmad, Editor-in-Chief of EDN and Planet Analog, has covered the electronics design industry for more than two decades.


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