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10 years, 5 months ago.
Board Consumption
Which consumption of NXP LPC1768, NXP LPC11U24, Freescale KL25Z?
2 Answers
10 years, 5 months ago.
That is a fairly unspecified question. Out of the box the LPC11u24 board can be the one using least, since you can power only the lpc11u24 and nothing else. The LPC1768 is by far the most power hungry. And the KL25 has quite some other stuff on it that cannot be directly shut down like on the LPC11u24. With some searching (for example on the handbook page) you can get current numbers. But it also hugely depends on what you shut down and what not.
However in the end if you really want a low power application, you probably will need to make your own PCB. Your only real alternative is the LPC11u24 directly powered, so everything else is shut down. Since the other stuff on the boards simply aren't chosen for their low power consumption.
10 years, 4 months ago.
Referring to the KL25Z freedom board, the out of the box current is 19.58 mA. This Tutorial may help you
http://mcuoneclipse.com/2013/10/20/tutorial-using-the-frdm-kl25z-as-low-power-board/
It will reduce the power consumption to 0.132 mA. Unfortunately CodeWarrier for MCU10.5 with Processor Expert is used to slow or power down sections of the KL25Z board. It would be very useful if somebody transferred the code to c++.
Hope this helps.
Problem is that quite some of the KL25 libs have hardcoded clock dividers and stuff like that, so changing the clock rate also changes those. However in principle you can just import mbed-src and change the clock source: http://mbed.org/users/mbed_official/code/mbed-src/file/64ad953ee6c3/targets/cmsis/TARGET_Freescale/TARGET_KL25Z/system_MKL25Z4.c. I have verified myself it works with those other clock setups (of course with limitations, because the libs aren't designed for it).
But the problem will be mainly (as usual) the other stuff around it, like the interface IC, LDO quiescent current, etc. Mbed now has deepsleep support for the KL25, which decreases its power consumption to 3uA (its clock sources are shut down, so only a handful of interrupts can wake it up, including a low-power wakeup timer)
posted by 22 Dec 2013