Hi, Kelly ! Look like you have just forgotten to turn off some periferal. I use 1F cap to power the msp430f149 (for RTC and memory save). I have tested it for one week main power off with a lot of energy left in the cap (the voltage dropped from 3.3v to 2.7v).
All the best ! Oleg Skydan P.S. Most of the problems with the msp430 are due to the lots of flags in the registers... ----- Original Message ----- From: "Kelly Murray" <k...@netnimble.com> To: <mspgcc-users@lists.sourceforge.net> Sent: Tuesday, May 04, 2004 7:54 PM Subject: [Mspgcc-users] sleep mode power consumption > Hello, > I've got a system where I use the MSP430 to turn off the power if the > system is > idle for some time, and then wake it back up if there is any user input. > > Of course, this is not possible, if the power is off, the MSP430 can't run! > But I use a .22F 3v capacitor that is charged up while power is on, and > then runs > the MSP when the power is off. > > The strange thing is that when I monitor the > voltage after power-down, the cap is loosing voltage rather quickly, > about .01 v per second, > until it hits 1.66V and then stays there. This should be less than the > voltage needed to run the MSP? > I think the specs say 1.8v. However, it does still seem to be running, > because it is still monitoring > the input and turns the power back on. > > My guess is that perhaps this behavior is "just lucky", that at 1.66v > the MSP is barely operating. > Alternatively, I suspect that because the 1.66v is also used as a logic > pin to shutdown the power, > it may be dipping below an "off" value for a tiny fraction of time, > just enough to give the cap > some juice enough to run the MSP, but not detectable by my voltmeter. > > Anyone have any ideas or suggestions? Isn't 1.66v too low to operate > the MSP4301232 ? > Any why is cap dropping so quickly from 3v, in shutdown mode, it should > draw very little power, > just enough to wake up every second and do a A/D reading. > > thanks for any input, > Kelly Murray > > > > > ------------------------------------------------------- > This SF.Net email is sponsored by: Oracle 10g > Get certified on the hottest thing ever to hit the market... Oracle 10g. > Take an Oracle 10g class now, and we'll give you the exam FREE. > http://ads.osdn.com/?ad_id=3149&alloc_id=8166&op=click > _______________________________________________ > Mspgcc-users mailing list > Mspgcc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/mspgcc-users >
