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Reducing SDA MCU Current When Idle

Question asked by Alex Dean on Jun 3, 2013
Latest reply on Jun 6, 2013 by Alex Dean

I've been looking into the power consumption of the Freedom KL25Z and the SDA portions are still drawing a lot of power even when the USB connection is unplugged.


I measured the current for P_SDA through J3 (cutting the trace on the back on the Rev C board). I get similar readings on the Rev E board.

  • When I power the board through the SDA USB connection, the P_SDA current is 21 mA.
  • When I power the board through the P5-9V_VIN connection the P_SDA current is 8.9 mA.


Is this second current normal? Is there a way to reduce it? It is still very large compared with the current of the KL25Z target MCU and LEDs.

I checked the /reset signal for the Debug MCU (SDA_RST) and it is asserted (0.5 V).


Thanks for any help!