The power budget for this design is based on the shelf life (inactive state) and active life (active state) requirements for the design. In the Bluetooth-enabled high-accuracy skin temperature flex patch, the CC2340R5 is configured in shutdown mode until the tactile switch (S1) is pressed and triggers the patch to wake up. Due to the overall low current consumption for the TMP119, the temperature sensor is powered using one of the CC2340R5 GPIOs. This reduces the total design shutdown current by removing the shutdown current of the temperature sensor from consideration. Thus, the current consumption of the design in shutdown mode is now limited to 165nA, which is primarily from the CC2340R5 MCU. As a result, the overall shelf life for this design is expected to be at least two years. This life span is limited by the typical shelf life of the battery and not by the charge storage. If using an alternate power source, shelf-life can change accordingly.

For active lifetime requirements, temperature patches can be expected to operate for up to a few days after the patches are attached to a wearer. Current consumption can be reduced by limiting the frequency of measurement, and by transmitting temperature data alongside the auto-advertisement pulse. Section 3.2.2.1 shows the current consumption results for the Bluetooth-enabled high-accuracy skin temperature flex patch. If the patch is active but not connected to the wearer, the patch can auto-advertise up to four times a second, measure temperature at 1 second intervals, and has an expected run time greater than 10 days. When connected, the active lifetime is expected to be around 1 day. Therefore, under normal circumstances, the patch remains in advertising mode most of the time and connects only as needed.