High current in LLS MKL27Z64VLH4

dusek_martin · ‎10-31-2019

Hi,

I have MKL27Z64VLH4, 1n87m mask.

It is soldered on a custom board without any other components around (only SWD connector is soldered).

Upon entering main function, I call:

int main(void)
{
smc_power_mode_lls_config_t lls_config;
lls_config.enableLpoClock = 0;

SMC_PreEnterStopModes();
SMC_SetPowerModeLls(SMC, &lls_config);
SMC_PostExitStopModes();

}

I can then measure 160 uA current consumption. However, it should be around 2 uA.

Can you please advise how to make MKL27Z64VLH4 consume 2 uA in LLS mode?

dusek_martin · ‎11-01-2019

I have it - I forgot to allow power modes:

SMC_SetPowerModeProtection(SMC, kSMC_AllowPowerModeAll);

Sorry for my stupid mistake and again thank you.

View solution in original post

mjbcswitzerland · ‎10-31-2019

Martin

Make sure that no pins are floating by either configuring pull-up/downs on inputs or driving unused ports. Floating pins cause quite high current consumption and you should find that there is a good saving in case you haven't ensured this yet.

Regards

Mark

dusek_martin · ‎10-31-2019

Hi Mark,

thank you for your reply. I have all pins configured as GPIO outputs. No matter if they drive 0 or 1, the current consumption is always 160 uA.

Debugger is disconnected from the board.

Do I have to turn off some peripheral/clock that is turned on automatically after POR?

kerryzhou · ‎10-31-2019

Hi Martin Dušek,

Please share your hardware power consumption test point, we need to check whether the test point just contains the MCU consumption.

BTW, after you download the low power code, please power off the board ,disconnect your debugger, then power on, and test the power consumption.

Wish it helps you!

If you still have questions about it, please kindly let us know.

Have a great day,

Kerry

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dusek_martin · ‎10-31-2019

Hi Kerry Zhou,

what do you mean by my hardware power consumption test point? I already mentioned that there is only MCU (and 6 pin SWD connector) on my board.There is no other component - no resistors, no capacitors, no other ICs.

There is 3V3 connected to all VDD pins of MCU, VFREH and VDDA. There is GND connected to all VSS pins, VREFL and VSSA. GPIOs are configured to drive zero. All other pins (USB_VDD, USB_D+, USB_d-) are floating. The power consumption is measured on 3V3 rail. It is not possible that the power is consumeed by any other component than MCU.

Yes, I already mentioned that I have debugger disconnected. I measure pwoer consumption after POR with debugger disconnected.

Can you please confirm that you can achieve 2 uA power consumption for MKL27Z64VLH4 with this code?

kerryzhou · ‎11-01-2019

Hi Martin Dušek,

Please test the FRDM-KL27 SDK code :

SDK_2.5.0_FRDM-KL27Z\boards\frdmkl27z\demo_apps\power_manager

1. modify power_manager.c, line 674 to:

ch ='G';

2. modify power_manager.c, line 266 to:

ch = 'S';//GETCHAR();

Then this is my FRDM-KL27 power consumption test result:

This board's chip is KL27Z64VLH4,1n87m mask, totally the same as you.

So, I highly recommend you test the official SDK code, just to check whether it is the software problem or the hardware problem.

Wish it helps you!

If you still have questions about it, please kindly let us know.

Have a great day,

Kerry

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dusek_martin · ‎11-01-2019

I have it - I forgot to allow power modes:

SMC_SetPowerModeProtection(SMC, kSMC_AllowPowerModeAll);

Sorry for my stupid mistake and again thank you.

kerryzhou · ‎11-01-2019

Good, thank you for the root problem sharing.

Wish it helps you!

If you still have questions about it, please kindly let us know.

Have a great day,

Kerry

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-----------------------------------------------------------------------------------------------------------------------

dusek_martin · ‎11-01-2019

Hi Kerry, thank you very much for confirming the current consumption. I will look at the SDK code.

kerryzhou · ‎11-01-2019

Hi Martin Dušek,

You are welcome!

If you still have question after you test it, just let me know.

Wish it helps you!

If you still have questions about it, please kindly let us know.

Have a great day,

Kerry

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
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