Current Consumption in stop3

[BasePointer]

Hi,

I've an interesting problem.

If I initialize the MCU with

"ICGC1 = 0b00111110; // 32768 enabled, loss of clock detection enabled"

the total current in stop3 is equal to 5.0uA.

If I initialize the MCU with

"ICGC1 = 0b00111101; // 32768 disabled in stop, loss of clock detection disabled"

the total current in stop3 is equal to 9.1uA.

An other problem here is that total current consumed is increasing over time in both condition. For example it starts with 5uA, but 3 minute later, it start increasing with steps about 1uA. 20 minutes later it becomes to 400uA and start falling. total 30 minutes later it falls to 5uA again and be stable.

The MCU is MC9S08LC60.

Thank you.

[Wings]

Let me guess .... you have a floating pin somewhere.

A floating input pin can accumulate a charge over time, and as that charge passing through Vcc/2 the input buffer will draw some current.

[BasePointer]

Hi Wings,

Thank you for your guess, but I have already checked all floating pins and define them as output.

Also this is not a chaotic behavior, always happens when the MCU enters in stop3.

You can see attached gif file for consumption.

Thank you.

BP

[BasePointer]

I also want to indicate that if I enter stop1 mode instead of stop3, total current consumption be 750nA and stable. My external hardware just uses 200nA (except MCU).

It also consumes 900nA in stop2 and stable.

Message Edited by BasePointer on 2007-03-0504:43 PM