K.h. Qin

KS22 currents of Low power mode are bigger than datasheet

Discussion created by K.h. Qin Employee on Oct 10, 2016
Latest reply on Oct 10, 2016 by Mark Butcher

Hi Dear Kinetis Experts

now my customer are using KS22 to design product,they are debugging the low power function.

Their target mode is STOP and VLPS, and the current they measured is much bigger than our datasheet.(STOP is about 580uA,VLPS is about 280uA)

Cause customer's own board they cannot send much details to us, so we can make the low power work on MAPS-KS22 then prove our function is OK.

 

Then I test it,

Hardware: MAPS-KS22 

Software: KSDK 2.0, demo code is "Power manager"

 

as the demo note, I didn't conncet any of M1 jumper.

 

 

I measure the IDD from the pins under M1, put the multimeter in series. 

 

I measured STOP and VLPS:

STOP Mode: the current is about 515uA, datasheet is 269.63uA, their diference about 245.37

VLPS Mode: the current is about 260uA, datasheet is 3.48uA, their difference about 256.52

 

 I also check other mode, seem it's like have a  "extra 250uA" add on it. I don't know where it come from?

 

Then I create a simple project based on hello world, shut down all module and delay for a while, then let MCU enter STOP/VLPS. Also I removed any suspect pull resister and super cap on the board.

I measured again: STOP became about 380uA, VLPS became 146uA, still got a extra about 100uA....

 

Also I remove FB1 and R23, to cut off VDD/VSS and VDDA/VSSA, no work...

 

Please help on it, thanks a lot!

 

Best Regards

Kehan

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