Lpc2000

Previous posts on this site by Robert (Philips Apps) indicated a power 
down current for the LPC2138 of about
50 uA in addtion to a RTC current of 20 uA.

The data sheet "LPC2131_32_34_36_38_2.pdf"  revison 20050516 indicates 
60 uA Typ, 500uA max at 85degrees

I would really like to know how to achieve this because the best I have 
achieved is 700 uA. This is with just a micro + Xtals + caps + a
RS232 converter circuit measured at 1 uA

I have based my design decision about this consumption - If it can't be 
achieved I need to find another micro, buy tools and re-layout!!!!!.

I am not the only person to find this. Correspondence with another group 
member below.

Any information would be most welcome

Owen Mooney

Correspondence:
------------------------------------------
Hi "relentless_6995"

I am mailing you because you put a post on the LPC2000 group

I am trying to put a LPC2138 into power down mode, but I am getting 700 
micramps
consumption. I've done the obvious things:  put unused ports as outputs 
to prevent parasitics
checked the uart circuit (less that 1 uA) the only other things on the 
board are the 2 xtals and their caps!

What power consumption did you get? and any hints?

Thanks

Owen Mooney
------------------------------------------

Owen,

Well that's curious - cause I also was able to only get down to 700uA as
well. I stopped at that point cause that will probably be okay for this app
but that is a lot higher than I expected. I do not have the RTC powered as
you might (you mentioned 2 xtals). I also hunted for floating inputs.
Powered down all the peripherals (though that seemed to make no difference).
Not sure what to try next.

I really would like to know what it "should be".

Can you copy our text so far to the group? Perhaps we could get further
along.

-------------------------------------------------------------
Bob Destremps