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LaurentLef
LaurentLef
Associate III
November 14, 2022
Question

Stop mode current with NUCLEO-32

  • November 14, 2022
  • 15 replies
  • 4960 views

Hi,

I am using the NUCLEO-32 STM32L011 kit and I want to put the MCU in stop mode to measure Idd. Everything seems to be going well but when I measure the current, this is 2.5µA versus 0.5µA announced in the datasheet when the stop mode is activated with the RTC active.

The measurement is performed on the JP1 connector therefore with a supply voltage of 3.3V.

I don't see what other components could consume this 2µA more, does anyone have an idea?

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15 replies

AScha.3
AScha.3
Super User
November 14, 2022

swd / jtag lines are all disconnected ?

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KDJEM.1
KDJEM.1
ST Technical Moderator
November 14, 2022

Hello @LaurentLef​,

Try to check if all free pins are set as analog.

When your question is answered, please close this topic by choosing Select as Best. This will help other users find that answer faster.

Kaouthar

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LaurentLef
LaurentLefAuthor
Associate III
November 14, 2022

Hi,

Thanks for these answers.

I run in release mode so the debugger is disabled.

Before entry in stop mode, I configure all GPIOs in input analog mode.

AScha.3
AScha.3
Super User
November 14, 2022

hi,

>the debugger is disabled < , yes. but not disconnected !

remove the jumpers - to be shure, no current can go there.

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LaurentLef
LaurentLefAuthor
Associate III
November 14, 2022

On the NUCLEO32-STM32L011 kit, there is no jumper on the SWCLK and SWDIO signals.

AScha.3
AScha.3
Super User
November 14, 2022

ok, right. so...just test, that there is no voltage .

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Piranha
Piranha
Principal III
November 15, 2022

Most likely the DBG_CR register is not reset.

Read more details about it there:

https://community.st.com/s/question/0D53W00001bnh8dSAA/how-to-enter-standby-or-shutdown-mode-on-stm32

LaurentLef
LaurentLefAuthor
Associate III
November 15, 2022

Hi,

Thanks for your advice.

To test consumption in STOP mode as simply as possible, I modified my software as follows:

1- Disable debug in low-power mode

2- Enable Low Power RUN

3- Disable RTC wake up

4- Disable SysTick interrupts

5- Configure all GPIOs in analog

6- Disable GPIOs clock

7- Enter in STOP mode with no return (RTC wake-up disable in step 3)

I measure the consumption during phases 1 to 4: Idd = 37µA, which is consistent for operation at 131072hz in MSI.

I measure the consumption in stop mode (after step 7): Idd=2.5µA, always 2.2µA more.

I don't understand why this overconsumption is my software or the NUCLEO-32 STM32L011 kit?

KDJEM.1
KDJEM.1
ST Technical Moderator
November 15, 2022

Hello @LaurentLef​,

Please check the parameters mentioned in the DS11100 and precisely in table 33 (as shown below).

0693W00000WIPQ3QAP.png 

Thank you for your contribution in the ST community.

Kaouthar

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LaurentLef
LaurentLefAuthor
Associate III
November 15, 2022

Thanks for this information.

Something bizarre: all the peripherals (Bor, PVD, ADC, and comparator) which use the VREFINT are off and yet the VREFINT_RDY_FLAG is at "1" in the SYSCFG_CFGR3 and PWR_CSR registers.

Does this mean that the Vrefint is active and therefore consumes 1.3µA in stop mode?

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