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Long Lifetime for STMicro SensorTile Modules with Single AA Battery

April 03, 2018 by Paul Shepard

RECOM has released a breakout board to connect the SensorTile from STMicroelectronics to RECOM's R-78S evaluation board. This technology enables the SensorTile to draw a stable 3.3V from a AA battery down to voltages as low as 0.65V. Engineers can therefore integrate a high-capacity single-cell AA battery into their designs and use test points to estimate the application's operation lifetime.

The R-78S3.3-0.1-EVM-1/STM-1 is a breakout board developed to be used with an ST Microelectronics STEVAL STLCS01V1 SensorTile module and the R-78S3.3-0.1-EVM-1 evaluation module to demonstrate IoT applications using the SensorTile module.

When powered directly through a coin cell battery, the input voltage can soon drop significantly after only a few hours of use. This causes the Bluetooth Low Energy transmission unit to stop operating reliably and leaves the energy from the coin cell battery wasted. This can be averted by incorporating the functionality of the R-78S which boosts a single-cell AA battery voltage of 1.5V up to a stable 3.3V - demonstrated by the R-78S Evaluation Board.

Test points for measuring voltages and currents make it possible to effortlessly calculate the typical battery lifetime for the SensorTile in both active and standby modes. Combining an AA battery and the R-78S guarantees a long application lifetime and at the same time reduces maintenance costs.

R-78S Evaluation Board

There is also an option to use external input voltage from other low voltage sources such as energy harvesting devices which are typical in remote applications. The R-78S Evaluation Board and the corresponding breakout board are available at authorized distributors.