S32K144EVB-Q100 VLPS current

[sureshjayagonda]

Hi,

I am using S32K144EVB-Q100 and running example program “power_mode_switch_s32k144” to determine power consumption in different operating modes. When switched to VLPS ( after entering VLPR) according to Table 7 (Power consumption ) current should be in micro amperes ( 29.8 or 39.1 depending on peripherals). But I am seeing 1.3 mA. UART interface shows that it is transited to VLPS mode but current ratings are not matching.

Can you please clarify is there something I am missing here or the program I am running needs any change. According to below section other clocks shall be disabled can someone point me to the code which is doing it ?

26.4.4 VLPR/VLPS mode entry

When entering VLPR/VLPS mode, the system clock should be SIRC. The FIRC, SOSC,

and SPLL must be disabled by software in RUN mode before making any mode

transition.

Can you please point to the code which is doing this.

Current is measured between VDD and VDD_MCU across R117 ( from schematic for EVB)

[Shuang]

Hi,

I can not get 35uA VLPS current. I can get 130uA VLPS current, which I take out R117 and supply 3.3V to VDD_MCU. I get 0.67V between VDD and GND when take out R117 and supply 3.3V to VDD_MCU. I do not kwon why there is 0.67V. All of the test base on s32k144EVB.

Attachment have my SDK component config and code. The code reference application notes of AN5425 and power_mode_switch_s32k144.

Could you help me?

Thanks!

[danielmartynek]

Hi,

Do you run the code stand-alone without a debugger? 

Otherwise, it cannot enter VLPS but an emulated stop stage instead.

Yes, FIRC, SOSC and SPLL must be disabled. 

The example doesn't do that.

Regards,

Daniel 

[sureshjayagonda]

Hi Daniel,

Thank you for the reply.

Yes i did run code stand-alone and entered VLPS.

I was not sure if the example was disabling these clocks or not, now its clear. Can you point to something which will help me disable the clocks in this mode and achieve required current ratings ? Help much appreciated 

[raresvasile]

Hi,

The last SDK release for S32K14x(BETA 1.9.0) contains the updated power_mode_switch example which disables those clocks prior to switching in VLPS.

Best regards,

Rares

[sureshjayagonda]

Thank you for updates,Rares.

I did download latest update and run that program. Even on new program current rating as not as expected.

Planning to use this processor for one of product with low power consumption, need to validate numbers before we decide on this.

Do you have any data which will help me co-relate the current ratings mentioned in  Table 7 (Power consumption ). 

I am not sure why when i run same program not getting correct ratings.

one more observation is RUN mode and VLPR mode current drawn is almost same when ran in FLASH, but in ram VLPR way more less than RUN. What is difference in both ?

[raresvasile]

Hi,

What is the observed current consumption?

One way to lower the value is to disable the SIRC in Stop modes.

The check box from the image has to be unchecked.

Please let me know the result.

Rares

[sureshjayagonda]

Current i observed is in range of 120uA VLPS mode without any changes to the example code

[raresvasile]

Hi,

1) The tab can be found in clock manager component. See the below picture

2) Please refer to the S32K1xx_Power_Modes_Configuration.xlsx attachment from the S32K Datasheet found in this location: https://www.nxp.com/docs/en/data-sheet/S32K-DS.pdf . You can take a look on the configurations for different power scenarios.

Best regards,

Rares

[sureshjayagonda]

Hi Rares,

How did u get to the window u put in the picture, i was not able to find that .

[danielmartynek]

Hi,

Also, PMC_REGSC[BIASEN] must be set to 1 when using VLP* modes.

Table 38-4, RM rev.7. footnote 1

I see the example doesn’t set the bit.

Regards,

Daniel

[sureshjayagonda]

I set that bit using API PMC_SetBiasMode(PMC,true), and output current is measured as 70uA. I am trying to get to 35uA VLPS current as per spec.