MCU similar to STM32F334 For low power Application ?

[Mitesh Vishwakarma]

Posted on June 12, 2018 at 14:43

Which MCU is similar to STM32F334 For low power Application. At present my MCU consuming 70mA . I don't understand why its taking too much current . I am using 8MHz External Cristal Frequency , TIMER HRTIM1, TIM2, TIM3, TIM17,

ADC1_channel 1,3,4,6,7 and 4 GPIOS. Is it consuming perfect amount of current ? My application require current between 1mA to 20mA.

[Tomas DRESLER]

Posted on June 12, 2018 at 15:20

Hello, have you tried the power consumption calculator in CubeMx? It shows to me at 72 MHz, 25 deg.C the core consumption ~23 mA, the HRTIM conso ~25 mA, further consumption is added by other timers, bus matrix, APB bridges and increased temperature.

The idea behind consumption redux is to lower the frequency of peripherals to lowest reasonable value and gate the clocks when unused - i.e. use sleep mode as much as possible, lower APB frequencies...

To answer your question - HRTIM is currently only available in F334 and H7 families, otherwise I'd recommend Lx families (0, 1, 4) where most features with lower dynamic consumption are implemented.

[Mitesh Vishwakarma]

Posted on June 13, 2018 at 12:34

Thanks for you reply .

I am using 8MHz frequency . i tried power consumption calculator for 8 MHz its approx 8mA. if i will not use HRTIM , what MCU should I prefer ?  and the most thing i can't use sleep mode.

[AvaTar]

Posted on June 13, 2018 at 13:21

Then perhaps a M0/M0+ device, i.e. a STM32L0xx, would suffice.

It is simpler, somewhat less performant than a F4 core, but less power-hungry and cheaper.

[Tesla DeLorean]

Posted on June 12, 2018 at 19:56

Frequently there is a lot of grinding in loops, ie HAL_Delay, and a bunch of others.

This can consume a lot of current while doing no work, use __WFI in loops dependent on clocks that tick from interrupts. Use __WFI in idle loops. Perhaps change the paradigm so you're not waiting on things, but use interrupts to advance tasks when actually ready.

Current tends to come from the things you attach and drive externally. Don't use aggressive slew-rate settings on things that don't change rapidly, ie a USART typically doesn't need to ram signals as is if they had 72 MHz edges, 2 MHz would suffice.