For a project with a microcontroller, I am using TPS63031 switching regulator from TI to convert the voltage from a Li-ion battery to a +3.3V dc stabilized power supply. During time, the microcontroller wakes up, takes samples from some sensors and then goes to sleep, then wakes up again and so on. During sleep periods, most of the ICs of the board are switched off (but not the regulator).
The problem is the following : I have noticed that when the current consumption of the board during the active periods is above or around 50mA, then during the following sleep period the current consumption is around 5.5mA. However, if the active current consumption is below 50mA more or less, then the sleep current is around 700uA. Except for the difference in the active current, there is no other difference between the two cases. The same ICs are supplied during sleep for both cases. I assume that the majority of this current is consumed at the regulator. However, I cannot understand
(1) why this difference exists and
(2) why the current is so high.
Theoretically, the current consumption of the rest electronics (except for the regulator) during the sleep periods should be around 200uA or less. Thus, I would expect that the total current consumption (with the regulator) would be around 500uA or so. Can anyone help me with this weird problem?
The problem is the following : I have noticed that when the current consumption of the board during the active periods is above or around 50mA, then during the following sleep period the current consumption is around 5.5mA. However, if the active current consumption is below 50mA more or less, then the sleep current is around 700uA. Except for the difference in the active current, there is no other difference between the two cases. The same ICs are supplied during sleep for both cases. I assume that the majority of this current is consumed at the regulator. However, I cannot understand
(1) why this difference exists and
(2) why the current is so high.
Theoretically, the current consumption of the rest electronics (except for the regulator) during the sleep periods should be around 200uA or less. Thus, I would expect that the total current consumption (with the regulator) would be around 500uA or so. Can anyone help me with this weird problem?