S32K148 pin configuration in sleep mode

[__invited__hari]

Hello,

I am using S32K148 in my project.

I could successfully put the processor in VLPS mode of operation.

I also configured all unused pins to 'PORT_PIN_DISABLED' state in software.

Observation is that the processor is still consuming lot of power (7mA).

May I know what precautions to be taken to get to ~50uAmps as mentioned in Datasheet?

Thanks

Hari

[danielmartynek]

Hello Hari,

The specification was taken with the internal pull downs enabled on all unused input pins and without any load on output pins. Table 7, footnote 1, DS rev9:

Do you run the application stand-alone without any debugger connected?

Thanks,

Daniel

[__invited__hari]

Hello Daniel,

Yes, I disconnected Debugger to measure the current consumed by the processor (which is 7mA). With debugger connected, it is consuming 10mA.

We do have external pull-downs (10K) connected for all unused pins.

Thanks,

Hari

[danielmartynek]

Hello Hari,
Are you sure it is not driving any external load?
What are the peripherals that are enabled in VLPS in your application?
Please see S32K1xx_Power_Modes_Configuration.xlsx that is attached to the DS – it specifies the MCU configuration for all the measurements in Table 7.
Also, have a look at Table 8, if you are using SPI master + DMA in VLPS, the consumption can be 7mA.

Thanks,
BR, Daniel

[__invited__hari]

Yes Daniel, you are correct.

Issue was with external oscillator.

After disconnecting the oscillator from MCU power supply, it only draws around 54uA.

Thanks,

Hari