Design win; Samsung Gear Fit 2 Pro range uses water-resistant pressure sensor from ST
ST cites the device’s accuracy and stability for go-anywhere smart wearables: an advanced chip design and water-resistant gel formula gives performance advantages and fast recovery between factory and store-shelf.
The intended end-user market is for smart watches and wearable fitness trackers whose owners want to go further with their devices and track performance across extra activities such as swimming. Samsung’s Gear Fit 2 Pro, the next generation of sports band, supports these trends with features such as built-in GPS, continuous heart rate monitoring, and larger on-board memory to do more even when not connected to a smartphone. ST’s waterproof pressure sensor, the LPS33HW, is part of the mix: resistant to chemicals such as chlorine, bromine, and salt water, it is suitable for pool or sea swimming, and will also resist soaps or detergents used when showering or cleaning.
Waterproofing pressure sensors, ST notes, creates challenges beyond just protecting the electronics. The LPS33HW is not only the most accurate, but also helps OEMs get their products to the store-shelves more quickly by recovering sooner after the stresses of manufacturing. Other sensors can require up to seven days to regain maximum accuracy after coming off the production line, but devices containing the LPS33HW are ready for action in less than half that time. This is due to the sensor’s high-performance built-in processor and the advanced formula of its water-resistant gel filling.
In addition to smart consumer devices such as wearables, other equipment including industrial sensors and utility meters can also use the robustness and high measurement accuracy of the LPS33HW. The 10bar pressure sensor can withstand being submerged up to 90 metres, and the very low RMS pressure noise of 0.008 mbar allows apps such as an altimeter, depth gauge, or weather monitor to deliver consistent and stable results. The sensor accuracy drifts by less than ±1 mbar per year.
When soldered to a circuit board during product manufacture, the accuracy is affected by less than ±2 mbar, and returns to normal after less than 72 hours – significantly quicker than similar water-resistant pressure sensors.
The LPS33HW in a 3.3 x 3.3 x 2.9 mm cylindrical metal package suitable for use with O-ring seals, is priced from $4.50 (1000).
STMicroelectronics; www.st.com