AVR-Chat

On Mar 24, 2006, at 3:46 AM, Tim Mitchell wrote:

> I have a remote control transmitter design where I'm trying to put the
> Tiny15 into Power Down mode. But although it appears to go into power
> down, it is still drawing 0.45mA. The data sheet says it should go  
> down
> to about 2uA. I have eliminated all external circuitry from the  
> design,
> it's just the tiny, so it's not a problem with connections to its  
> pins.
>
> Has anyone done Power Down and got down to the 2uA in the data sheet?
>
>
> This is the code to put it into sleep
>
> 	in tempB,mcucr
> 	andi tempB,~((1<<SE)|(1<<SM1)|(1<<SM0))
> 	ori tempB,(1<<SE)|(1<<SM1)
> 	out mcucr,tempB
> 	sleep


Some more things to look at:

- You say you have eliminated "all external circuitry"; are you sure  
that you have all input pins either pulled up (possibly by the  
internal pullups) or down? Digital input pins at in-between voltages  
can draw quite a bit of current.

- Is it possible that you have an internal pullup turned on and are  
then grounding that input? This would add 250uA or so of pin current  
to your supply current.

-- 
Ned Konz
ned@bike-nomad.com