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
>

Have you got the peripherals turned off?

- Bandgap Reference (turned on if you have BOD enabled (BODEN fuse))
- Watchdog (WDE) (15uA) (also used for level-triggered or pin-change  
interrupt to wake from sleep)

With the watchdog timer all the way off, the only way to wake from  
sleep is the RESET pin, so I assume that you are using the watchdog  
timer.

I'm not sure whether Power Down mode disables the BOD reset or not;  
it may turn off the BG reference too.

-- 
Ned Konz
ned@bike-nomad.com