AVR-Chat

AVR-Chat@yahoogroups.com wrote:
> 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?
>> 
> 
> 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.

We aren't using the watchdog timer to wake it, we are using pin change
interrupt, and the watchdog timer is disabled (as I understand it the
pin change interrupt uses the watchdog oscillator, but that isn't the
same thing as the watchdog timer - I think). I'm not sure what you mean
by "watchdog timer all the way off" - I might be missing something
important here.

As far as I can see, there aren't any peripherals enabled, we've tried
(as an experiment) turning off the internal pullups and fitting 1M pull
up resistors externally but this has not made any difference.

-- 
Tim Mitchell
tim@sabretechnology.co.uk
http://www.sabretechnology.co.uk