S32K314 Sleep Mode

[jfranklin]

Hello, 

I'm working on putting the S32K313 into sleep mode. After following the steps and executing the WFI, and can see it go into Sleep Mode, but it only drops the current from ~40mA to ~30mA. (All peripherals are disabled) Based on my reading of the datasheet, I should be getting into the ~10uA range when I enter Sleep Mode. Can you help determine roughly how much the current should drop when I enter Sleep Mode?

[petervlna]

Hello,

I agree with jfranklin.

Seems you are not in low power mode. Please refer to reference manual, mode entry chapter:

Best regards,
Peter

[Gene742Nelson]

Hello!

On the S32K313, simply executing WFI usually puts the MCU into a light sleep state, which explains why your current only drops from ~40 mA to ~30 mA. The datasheet’s ~10 µA figures apply to the deepest low‑power modes (VLPS/STOP) with clocks and regulators shut down, and on a bare MCU rather than a dev board. To reach those numbers, you need to configure the proper low‑power mode registers, disable all system clocks and peripherals, and account for extra current draw from board components like regulators, LEDs, or debug circuitry. In short, ~30 mA is expected for light sleep, while the microamp range is only achievable in deep sleep modes with minimal external load. 

[jfranklin]

Hello, 

Thanks for the information. As far as I can tell I've followed the steps in the RM. However I haven't seen any distinction between a Deep Sleep and Light Sleep. Does the RM explain that difference and what is needed to get to Deep Sleep?

[petervlna]

Hello,

Please refer to the reference manual: 41.5 Standby mode entry sequence

You can also use example:

https://community.nxp.com/t5/S32K-Knowledge-Base/Example-S32K312-Standby-mode-amp-Standby-RAM-and-PA...

And this AN dealing with lowe power modes of S32K3

https://community.nxp.com/pwmxy87654/attachments/pwmxy87654/S32K/24240/1/S32K3xx%20Low%20Power%20Man...

Best regards,

Peter

[jfranklin]

Hello, 

That chapter is the main chapter that I have been referencing for my research. However in that chapter and throughout the RM, there isn't a distinction made between a Light Sleep and a Deep Sleep. Is there a specific place in the RM that makes that distinction?

[petervlna]

Hello,

There is no such "Light Sleep and a Deep Sleep" thing.

You have these 3 modes:

Low power mode is Standby. You can configure which peripherals are active in this mode (if supported).

Please refer to Chapter 42 Power Management Controller (PMC for S32K34x, S32K322, S32K324, and S32K314).

Best regards,

Peter

[jfranklin]

So the response above by Gene742Nelson is entirely incorrect?

[petervlna]

Hello,

So the response above by Gene742Nelson is entirely incorrect?

No. I would say his wording is not accurate. But in principle he is right.

Simply stick with reference manual and datasheet terminology.

There is STANDBY mode - which is low power mode. There you can have multiple peripherals OFF/ON.

Best regards,

Peter