Other Parts Discussed in Thread: TPS61322, TPS61299
Hi, I'm designing a battery power device (2 alkaline) that will sleep for 5-10 minutes, wake up for a few seconds, collect some information and sleep again.
The device uses an STM32L4 low power uC, when it wakes up it powers up some sensors to take readings and then powers them down and sleeps again. The uController will run as low as 1.8 volts but some of the sensors need at least 3.3 v.
I note that in the data sheet for this device in section 12.3 it states that when the device is disabled the output voltage follows the power source voltage.
This device appears to be fairly inefficient at low currents (e.g., ~3 uA).
My question is would it be feasible for the TPS61221 to be disabled, thus powering the uC directly from batteries. Then when the uC wakes up it enables the TPS61221, then enables the sensors that require 3.3v, then when it is ready to sleep it would disable the TPS61221 and then sleep.
My concern is whether during the transient conditions of enabling and disabling the TPS61221 there will be a consistent (although varying from battery voltage to 3.3 v) voltage supply so the uC can continue to run.
Thanks for you help,
Jerry
