Power management tips

AN3147

22/25

DocID17035 Rev 3

5.5

Minimizing power consumption

The following recommendations can help you choose the right configurations to minimize

the power consumption of your device in your application:



Switch off all unused peripherals (peripherals are switched off by default) and use the

PCG feature (through the CLK_PCKENRx registers) to disable the clock provided to

the unused peripherals (these clocks are disabled by default).



All unused pins must be connected to a defined logic level. One of the option is to

configure them as output low level. Make sure there are no unused I/O pins configured

as a floating input. This needlessly leads to a high consumption.



Use Wait mode if you need external wakeup capability in low power mode and if some

peripherals have to remain active.



consumed power.

Thanks to the internal regulator, which supplies internal structures of the MCU, there is

no major difference in the MCU consumption but the difference could be visible on an

application level, e.g. due to the current flowing through pull-up resistors out of the

MCU.



Use Low power run mode and Halt modes as much as possible. To achieve this, you

need to shorten the time spent in the Run mode, for example by using the highest clock

speed in Run mode.



When a low power mode cannot be used, use the minimum possible frequency for your

application. You can select the frequency value that meets your requirements.



Use the dynamic control of pull-up configuration if possible. See Section 5.2: GPIO

initialization on page 20 for a the detailed description.