AnsweredAssumed Answered

K60 (5N22D) current consumption in LLS

Question asked by Mike Kinney on Dec 23, 2016
Latest reply on Feb 6, 2017 by Hui_Ma



We are migrating our project from K60DN512ZVLL10 to K60DN512VLL10 (non-Z revision). The old K60 is a Kinetis 100Mhz Rev.1.4 device (mask set 4N30D) and the new one is Rev.2.5 (mask set 5N22D).


There are several problems that we've got after the firmware adjustments. The most important one is the LLS mode current. With the initial K60 version (Z-revision) the LLS current was about 0.03mA, but with the 5N22D revision we get as much as 1.7mA! Our device is battery operated so the power consumption is critical.


What was done:

- eliminated all possible reasons related to hardware (changed the processor on PCB back to the old version - everything is fine, LLS current is 0.03mA)

- implemented all changes described in AN4445 (this document only describes migration to Rev.2.2, how about Rev.2.5?)

- in order to check for Rev.2.2 - Rev.2.5 changes we also checked AN4526 (it describes migration to 120MHz processors, but still it have some useful info, such as e.g. SIM_SOPT1CFG register needed to control USB voltage regulator in SIM_SOPT1 that was not mentioned in AN4445)

- checked the latest Reference Manual version

- checked all Errata Documents for 4N22D and 5N22D mask sets (nothing related to out problem)

- created a separate project for the new K60 that just switches the processor into LLS mode (still 1.7mA)



- can someone confirm that it is possible to achieve 0.03mA with K60 Rev.2.5 in LLS? (it should be possible according to the datasheet)

- what else we can check or change? Is there a migration guide for K60 100Mhz that covers also 5N22D?

- USB is not working either, could this be related? It doesn't look like the USB module has changed between these revisions.




Finally got 0.05mA in LLS on K60 rev.2.5. One of the problems was the USB voltage regulator that was not disabled properly (because of new SIM_SOPT1CFG register unlocks SIM_SOPT1 register bits to control the voltage regulator).

However the USB problem remains! When USB is connected Windows error appears: USB Device Not Recognized. Device status is "Windows has stopped this device because it has reported problems. (Code 43)". What could be the problem with that taking into account the migration problems that we had? It is also strange that if the new MCU is flashed with a firmware for rev.1.4 then USB works fine!