STM32F4 low power clock settings

[matas]

Posted on October 16, 2015 at 10:57

Hey, I need to decrese the STM32F401 consumpion to a minimum, the only problem is that I am using SDIO to interface a microSD card. Since the current consumption depends heavly on the clock is it possible to use HSE (8MHz) to the system while still driving the SDIO with PLL?

[matas]

Posted on October 16, 2015 at 16:46

Thanks a lot everybody, I'll post my findings here if I'll find any :)

[matas]

Posted on October 20, 2015 at 08:13

I found a way to reduce the current consumption, it was rather simple. Instead of entering the stop mode in the middle of the program (when the sensor is converting measurements), I moved the measurement to be taken durring the standby mode since the sensor is always supplied with power and is not taking much of it. The results are taken from the sensor the next time processor wakes up. Since stop mode is removed, there is no need to setup the Alarm every time and reinitiate the systemclock after stopmode. Now without the microSD card the device takes average 25uA.