Kinetis K60 RUN to DEEPSLEEP transition time.

[przemyslawostro]

Hi,

I am working on a project where low power consumption is a priority.

At the moment I am using LPTMR (driven by RTC clock) to wake MCU every 1 ms  for about 50 us and get back to VLLS1 mode.

When I disable the LPTMR wakeup the current consumption in VLLS1 mode is about 20uA. But when it wakes up every 1ms the average current consumption grows to about 2mA.

I set GPIO pin high when the MCU is woken up and I clear the pin just before it goes to deepsleep (just before I call WFI).  On the scope I can see that the most current is consumed just before wakeup and a few ms after GPIO pin is set low (so a few ms after it should go to deepsleep).

So my questions are:

1. How long does it take to transit from RUN / LVPR mode to VLLS1 mode?

2. How much current K60 consumes during that transition from RUN / LVPR mode to VLLS1 mode?

3. Can I get average current consumption on level about 300uA (still waking up every 1 ms)?

Thanks for help.

John

[jeremyzhou]

Hi John,

1. How long does it take to transit from RUN / LVPR mode to VLLS1 mode?

It depend on the frequency of the System clock, the MCU will enter VLLS1 mode after execute the _wfi() function.

2. How much current K60 consumes during that transition from RUN / LVPR mode to VLLS1 mode?

There's no specific description about the level of the current during MCU enter VLLS1 mode from RUN or VLPR mode.

3. Can I get average current consumption on level about 300uA (still waking up every 1 ms)?

I'd like to suggest that you should choose the VLPR instead of RUN when MCU executes the codes and lower the supply voltage to reduce the consumption as possible as you can.
Have a great day,
Ping

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