Too high power consumption in low power mode

[AFaustas]

Hello here.

We are designing a device which must work in very low power mode and boot Linux only when needed. We chose i.MX93. It has Cortex A55 cores which can be used for Linux and also a Cortex M33 core. I use i.MX93EVK development board. I built a "Hello World" example and wrote it into eMMC. Then set switches to "eMMC/SDHC1" boot. I noticed that the board still uses 1W (200mA at 5V). This is way too much. When in low power mode I expect that only M33 is started while A55 and DDR refresh logic are disabled. Starting at such high power consumption and then programmatically disabling everything what we can is not an option for us.

Could someone tell me, how I could get a power consumption which would be actually low. I expect initial power consumption less than 10mW.

Best regards,
Faustas

[Will_Robertson]

Hi @AFaustas 

I'd just add to what @AldoG said by saying that a very large proportion of the power consumption of a board is often the peripheral chips on the board. Looking through the device tree for the board can often give an idea of which peripherals can be disabled or set to a low power mode to greatly reduce power consumption in sleep mode.

It may also be worth considering looking at the i.MX 8M Plus Evaluation Kit Enabling Power Measurement - the IMX8MPLUS is in some ways similar to the i.MX 93 and the 8MPLUSLPD4-PEVK allows power consumption to be measured in detail:

https://www.nxp.com/design/design-center/development-boards-and-designs/8MPLUSLPD4-PEVK

Will

[AldoG]

Hello,

Please have a look to the following App Note:
https://docs.nxp.com/bundle/AN13917/page/topics/reducing_power_consumption_0.html

In short you may custom your boot image to try to achieve your target consumption.

Best regards/Saludos,
Aldo.