Working with the Boron it seems you can only get down to 4.9 mW in a timed sleep.Why is this? The Nordic nRF chip can get down to ~1uA with RTC. So where is the power going?
It’s a bug in recent versions of Device OS on the Boron. The modem is not going into sleep mode properly, which is the bulk of the excess usage.
There is current leakage through the antenna switch and UART that has always been the case since sleep modes were added in 0.9.0 as well.
We expect to have all of these issues addressed in the 4th quarter of 2019, and then the SLEEP_MODE_DEEP current (which does not allow timed sleep) should drop to around 180 µA. Stop mode sleep, which does allow timed sleep, is a little higher, but I don’t have an exact number.
Thank you for giving the community real technical answers. Glad to hear there is internal work being done to improve the sleep current. Look forward to those future firmware.