Lowest power on STM32F105RC

[eliot]

Posted on March 29, 2016 at 10:03

Hi:

I'm developing with an STM32F105.

On datasheet, lowest power is on StandBY mode, and it consumes about 4uA, however I get about 300uA, and I don't know what I'm doing wrong.

On my program, it is all what I do:

    gpios_init();    //All gpios as analog input

    systick_init();  //Systick to 1000 ticks per second.

    Sleep(5000);   //Sleep 5 seconds to restart and program.

    //PWR_EnterSTANDBYMode();

Is it starting-up with any peripheral running?

How can I get the lowest consumption?

Thanks

#stm32f105-low-power

[Walid FTITI_O]

Posted on March 29, 2016 at 11:44

Hi cuesta.eliot,

I suggest that you run the ''Standby'' example in the library package and see if you get the desired consumption. If it is not, it will be related to your hardware setup.

You find standby example in both following libraries:

• http://www.st.com/web/catalog/tools/FM147/CL1794/SC961/SS1743/LN1897/PF260820

  (the latest library which is recommended) at this path :

STM32Cube_FW_F1_V1.3.0\Projects\STM32F103RB-Nucleo\Examples\PWR\PWR_STANDBY\Src

• http://www.st.com/web/catalog/tools/FM147/CL1794/SC961/SS1743/LN1939/PF257890

  at this path (RTC enabled , should be commented to get only standby consumption):

stm32f1_stdperiph_lib\STM32F10x_StdPeriph_Lib_V3.5.0\Project\STM32F10x_StdPeriph_Examples\PWR\STANDBY

-Hannibal-

[eliot]

Posted on March 29, 2016 at 13:59

Hello Hannibal:

Thanks for answering.

My program is based on your second link to STM32F10x examples.

I have programmed too the first example that you have give me, and it stills consumming 300 uA.

I don't know what of hardware can be wrong. I have two external oscillators, programming pins, and GPIOs has been configured as analog input.

Thank you.

Regards.

[dthedens]

Posted on March 29, 2016 at 17:40

Is this your own board or a dev board?

The spec is the very best the micro can do, but power consumption is greatly affected by external components, even capacitors leak.

this link has some  good information on low power.

http://www.ganssle.com/reports/ultra-low-power-design.html

[eliot]

Posted on March 29, 2016 at 18:02

Hello David:

Effectively I had an error on hardware design. No, it is not an evaluation kit.

I was switching on the STM with an external switch and it has a 10k resistor pull down.

3.3V / 10k = 300 uA.

The 300uA that I was losing.

Now I could drop the power consumtion to 50uA on Stop mode and a lot on StandBy (I have not enough precission, but less than 10uA).

Next step: Try to drop the power consumption on Stop mode.

I going to get a look to your link.

Thanks for your answer.

Regards.

[Walid FTITI_O]

Posted on March 29, 2016 at 21:08

Hi cuesta.eliot,

It is nice to hear that you have found the hardware cause.

Keep up the good work.

-Hannibal-