topic Re: K60 current consumption in Kinetis Microcontrollers

K60 current consumption

lukas — Mon, 11 Jul 2011 13:53:23 GMT

I prepare the suitable platform for our new battery powered industrial device.

The kinetis platform is the best what I find as the single chip solution but the

current consumption values in datasheet are in my case you of reality.

I have k60 tower.

The values what I measured are evidently belongs to column TBD :-)

OK, I am liar, the Run mode current is in range of datasheet parameters 53,6mA.

The Wait current from dataseet Typ. 35mA, my measure 46,2mA

Stop mode current Typ. 0,4mA, my measure 6mA

VLPS mode Typ. 50uA, my measure 1,6mA

LLS Typ. 12uA, my measure 0,8mA

Are those values better with K40 or they will be improved in next version?

What are your measurements?

I used the Fluke 8025 A multimeter

Lukas

Re: K60 current consumption

BasePointer — Tue, 12 Jul 2011 04:24:05 GMT

Hi Lukas,

I'm also interested in this subject. For our application, continuous RTC consumption and wake-able state sleep consumption are important.

I have checked K30 datasheet and it is written:

Sleep mode consumptions:

Low leakage stop mode current at 3.0 V -> 12uA

Very low-leakage stop mode 3 current at 3.0 V -> 8uA

Very low-leakage stop mode 2 current at 3.0 V -> 4uA

Very low-leakage stop mode 1 current at 3.0 V -> 2uA

Average current when CPU is not accessing RTC registers at 3.0 V -> 0.7uA (I don’t know exact meaning)

Run mode:

Run mode current @100 MHz — all peripheral clocks enabled -> 66mA

I also don’t know the exact functionality differences between stop modes, but stop3 mode consumption is OK for our battery.

And they said that 66mA in full run mode at 100MHz. Can I expect 6.6mA if CPU has clock only 10 MHz?

For your measurement, I’m sure there is something with hardware. You might have to change some I/O state before measurement depends on hardware status. Because they have put all these values into datasheet, they cannot say sorry later, I’m sorry

Re: K60 current consumption

lukas — Tue, 12 Jul 2011 12:32:13 GMT

Hi,

I am doing my measurement on the example tsi_low_pwr.

I measure current trough J8 header.

I find out that the J-link must be dissconected because it takes about 1,2 mA

I know that there is errata with some problem in one of low power modes.

It is interesting that the system could not wake up by reset from low power stop modes -

when reset occurs it falls to inappropriate state - and the mcu power must be turned off and on.

Regards

Lukas

Re: K60 current consumption

lukas — Fri, 15 Jul 2011 19:08:38 GMT

there is sometimes strange behaviour during execution the TSI low power example.

Espacially when exiting from low power stop modes and low leakage stop modes.

Sometimes the core lockup occurs, very often is not possible or difficult to wakeup.

Re: K60 current consumption

TomSkwara — Sat, 16 Jul 2011 02:21:39 GMT

Your inaccurate current draw measurements may have something to do with hardware errata on the TWR-K60N512 Tower Controller Module. Here is a link to the detailed document:

http://cache.freescale.com/files/microcontrollers/doc/errata/TWRK60N512HWER.pdf?fpsp=1&WT_TYPE=Errata&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=pdf&WT_ASSET=Documentation

Here are some details that apply to rev A, B and C boards:

TWRK60N512_04

Potentiometer Voltage Reference

Description

The potentiometer is connected between VREFH and VREFL. These supplies are derived from the P3V3_MCU. The potentiometer works as expected but the supply connection loads the processor voltage rail and limits the ability to measure the power consumed by only the MCU.

Workaround

The potentiometer can be removed to measure the current consumed by only the MCU.

Status

Starting with revision D of the schematics, the supply voltage to the potentiometer was changed.

Re: K60 current consumption

lukas — Mon, 18 Jul 2011 15:14:56 GMT

Thanks for very usefull help and tip.

Regards

Lukas