Il 10/05/2013 10:19, Shashank Maheshwari ha scritto:
> Thanks for that input Manca. This group is a real saver! So I was just
> trying out all the alternatives and following is the result :
>
> Before going into sleep mode WFI(), I turn on the LF Oscillator at its
> lowest frequency (600/64 = 9.575kHz). I turn down the IRC oscillator output
> power, IRC power, ADC, XTAL, Watchdog, DAC and analog comparator. However I
> have not turned down the Flash Power (I guess if I turn this down, this
> will hang the system as how would the processor fetch code ?)

yes it should. I think you could turn down everything except flash, ram
and something to awake the microcontroller.

>
> Now I get a sleep current of 1.48mA which is still pretty high. I have
> turned all the GPIOs as outputs and driven low.
>
> What else can I do?

Not so much. I have no data to say how changes the current consumptio
for frequency less then 12 MHz. And 1.48 mA is not so bad for an ARM
sleep state. The problem is that on microcontrollers there are 2 real
data: dynamic current consumption and static current consumption. The
total current consumption will be always higher or equal then the static
current consumption. Don't having these 2 data I should suppose that the
trip point is that you will notice no sensible current reduction
reducing the clock frequency. I could think it should be around 1 MHz
considering the silicon technology of the LPC11Axx. Start a New Thread

Isn't it possible to place the code that enters sleep mode in RAM,
interrupt vectors in RAM, interrupt routines in RAM and disable flash power?
When you wake up just enable flash before jumping to any code section in
flash.

I have no experience with sleep modes or power consumption management but
I'd try to disable flash. It's quite easy to place code in RAM.

Regards,
Bernardo Marques. Start a New Thread

Hey

So finally after setting up the GPIO pins right, turning off the
peripherals as explained in the earlier threads (including flash), turning
on the LFO while I turn off the IRC and PLL, I get the power down current
of *700uA. *
*
*
This is still too much for a battery operated system. Is it possible to go
below this on LPC11A14 ?

I might be wrong but I think given the fact that this IC does not have a
PMU neither Power Modes this wasn't really meant for an ultra low power
applications. Its on chip EEPROM and temperature sensors were a big
attraction for the selection of this uC. This eventually resulted in a huge
trade off for power.

I would still be delighted if this could go lower. I am expecting something
around 100uA which at max might stretch to 200mA.

Should I change the uC and go for a LPC1114(33 pin, XL) or shall I do more
head banging on the same system (if the goal is achievable)?
Even if I change the IC I will still have to run it on Deep Sleep mode as
Deep Power Down mode wont be possible for the application !

Best Regards
Shashank Start a New Thread

Il 10/05/2013 19:59, Shashank Maheshwari ha scritto:
> Hey
>
> So finally after setting up the GPIO pins right, turning off the
> peripherals as explained in the earlier threads (including flash), turning
> on the LFO while I turn off the IRC and PLL, I get the power down current
> of *700uA. *
> *
> *
> This is still too much for a battery operated system. Is it possible to go
> below this on LPC11A14 ?
>
> I might be wrong but I think given the fact that this IC does not have a
> PMU neither Power Modes this wasn't really meant for an ultra low power
> applications. Its on chip EEPROM and temperature sensors were a big
> attraction for the selection of this uC. This eventually resulted in a huge
> trade off for power.
>
> I would still be delighted if this could go lower. I am expecting something
> around 100uA which at max might stretch to 200mA.
>
> Should I change the uC and go for a LPC1114(33 pin, XL) or shall I do more
> head banging on the same system (if the goal is achievable)?
> Even if I change the IC I will still have to run it on Deep Sleep mode as
> Deep Power Down mode wont be possible for the application !

Technically having an EEPROM you should design your application to
switch totally off the microcontroller. Start a New Thread