STM32L100C-Disco board standby mode

[Eli Garay]

Posted on May 02, 2018 at 23:01

When using the STM32L100C-Disco Board i use the command,

HAL_PWR_EnterSTANDBYMode()

but when I measure the current on I_DDpins using a multimeter on the uA setting (using a Fluke 87), I read a value of ~282uA, which is higher than the spec sheet which says ~3uA. Any ideas why? Are there additional commands that need to be called prior to entering standby mode? Could it be the type of multimeter I am using? I disable the wakeup pins and I made all the pins Analogue inputs before entering standbymode. 

Thanks.

[Bogdan Golab]

Posted on May 04, 2018 at 20:47

Looks like a current leakage.

I found interesting note for STM32L15x (not exactly the one you use but also from L1 series):

http://www.st.com/content/ccc/resource/technical/document/application_note/0f/2d/e5/5d/4b/63/48/24/DM00087687.pdf/files/DM00087687.pdf/jcr:content/translations/en.DM00087687.pdf

 

Page 7:

'The slilicon limitation present on STM32L15xxB PB7 pin may affect current consumption measurement. When PB7 is configured in analog mode and no PVD level is selected, an internal pull-up is activated on PB7 pin. This may induce current flow through external components such as resistors or diode on the STM32L1-DISCOVERY board. To measure only the MCU current consumption, two solutions are possible:

•Disconnect the LD3 diode connected to PB7 internal pull-up

•Configure PB7 as an input and connect PB7 pin to GND to minimize current consumption.

'

I do not want to say that this is the root cause....

[Eli Garay]

Posted on May 10, 2018 at 08:06

I tried what you suggested, but it did not work. Any other suggestions?