High consumption of SoC supply rail in Deep-Sleep Mode

[damienvielpeau]

Hello everybody,

I am evaluating the power consumption of the imx.6 SoloLite using the Freescale evaluation kit.

I follow the Application Note 4580 "i.MX 6SoloLite Power Consumption Measurement".

in Deep-Sleep mode, I obtain a value very high comparing to the Application Note :

It concerns the rail  VDD_SOC_IN + VDD_PU_IN,  I obtain 5.4mW whereas the Application Note indicates 0.550mW !

The other measurements are normal.

My procedure to make the measurement is :

- Configure the Linux kernel to disable all Multimedia and Graphics drivers :

     Device Drivers > Multimedia Support > OFF

     Multimedia Drivers > Graphics Support > OFF

- Build "core-image-minimal" with yocto.

- Boot & put the system on deep-sleep mode executing :

     $ echo mem > sys/power/state

- Measure voltage between pins of a resistance 0.020ohm soldered at SH3 to deduce the current of the channel, then the power consumption.

I think my process of measurement is correct because the other measurements I made are normal.

Maybe I need to configure something differently ?

Thanks for your help

[jamesbone]

Hello Damien,

It is not correct your method of measurement you need to actually measure the current on SH3.  Not just to deduce the value.  Since the current it is directly affected to enter into the deep sleed mode.

[damienvielpeau]

Thank you for your reply,

To 'deduce' (maybe its not the good term) the value, I measure the voltage between the pins of the resistor then I divide by the value of the resistor, as indicated in the Application Note.

Do you mean it is better to remove the resistor and measure directly the current using an ampermeter ?

If so, I will try.