STM32L1 Stop Mode various consumption at different Systemclocks

[marcogimm9]

Posted on January 07, 2013 at 11:43

Hello,

I am just trying out the Stop Mode with my STM32L1 Discovery. But I think there is something I do wrong. When I use the HSI as Systemclock the consuption is higher then using the MSI. Also different MSI values cause different consumtion. I thougt, that the HSI an MSI automatically switched of, when entering the Stop Mode and the consumption always is the same.

I am using the RTC to generate an Interrupt every 4 seconds then I enter to the Stopmode.

RTC_WakeUpCmd(ENABLE);

PWR_EnterSTOPMode(PWR_Regulator_LowPower,PWR_STOPEntry_WFI);

RTC_WakeUpCmd(DISABLE);

I also tried

''ADC_Cmd(ADC1, DISABLE);''

and

''PWR_UltraLowPowerCmd(ENABLE);''

but nothing changed.

#low-power-stop-mode

[Tesla DeLorean]

Posted on January 07, 2013 at 19:56

Aren't the internal RC oscillators the least efficient means of generating a clock? To the point that ST precludes the use of the LSI to maintain the RTC off VBAT?

[marcogimm9]

Posted on January 07, 2013 at 22:16

I am using the LSE as RTC Clocksource, but what about my problem. Aren´t the Clocks switched off during STOP Mode, independend of witch one is used?

[Tesla DeLorean]

Posted on January 07, 2013 at 22:45

They are documented to turn off, do you have other interrupts running (SysTick?), how about other pins being driven?

What currents are you seeing?

Are you testing this on an STM32L-Discovery, or something else?

[marcogimm9]

Posted on January 08, 2013 at 00:13

Only the RTC and USART Interrupts are running, no Systick. There are some driven Pins for the LCD an USART. I tryed it out on the Discoveryboard. The consumptim while Stopmode is from 100µA (MSI 512 kHz) to 220µA (HSI 12 MHz).

Thanks for your help!!