STM32L4 current consumption is more than expected.

[dhs]

I am working with a NUCLEO_l452RE, temperature 25°C, 1.8V, and I am measuring current on JP6, so I tried to reproduce:

 

I set up MSI@1Mhz, I got 280uA, much more than 100uA which I was expecting.

Later with MSI@24Mhz, I got 3.24 mA, 135uA/MHz, closer to 100uA.

I disable UART, RCC, LED, disconnect the USB port, and used an external power supply.

There is a bias in current consumption about 180uA? there is something I can do to mitigate it?

On en.fistm324l.pdf I found another number of current consumption, I am very confused about what to expect.

 

[Piranha]

Some factors are still relevant:

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

[dhs]

The link is about deeper low-power modes, I ran my own tests and got matched consumptions with ST technical data from stop 1 and deeper modes but, I got about 180uA more for other modes, RUN, range 1 and 2, LPRUN and SLEEP

It is possible setup a project using CUBE MX for 100uA @ MSI = 1MHz run mode?

I have a few núcleo-64 borads all L4 series

Regards, Daniel

[Piranha]

As I said, issues 2, 3 and partly 4 are relevant for all low-power modes.

[Sarra.S]

Hello @dhs​,

first of all, I advice to always refer to the datasheet to know the current consumption reference.

for the NUCLEO_L452RE, in LPRun mode at 25°C and MSI = 1MHz, the current consumption should be between 130 and 170 μA.

 

Are you sure all peripherals are disabled ?

also, it's useful to set all free pins as analog in CubeMX to reduce the power consumption

 

Thank you!

Sarra

[dhs · Accepted solution]

Finally, it started working, I am reading:

• 65uA MSI @ 1MHz sleep run
• 130uA MSI @ 1MHZ low-power run

I had a mix of problems

• My tester connected to JP6, doesn't let the microcontroller reset properly, I had to disconnect and connect again, and later I changed it to one with less impedance.
• Sometimes I forgot to include HAL_SuspendTick()

I am used to working with msp430, peripherical are more low-power targeted, but stm32l4 is starting to like me very much.