Ah, thank you. I have noticed that many voltage regulator circuits will draw more power than the msp430. Yours is an interesting solution.
-----Original Message----- From: mspgcc-users-ad...@lists.sourceforge.net [mailto:mspgcc-users-ad...@lists.sourceforge.net] On Behalf Of Kelly Murray Sent: Tuesday, May 04, 2004 1:21 PM To: mspgcc-users@lists.sourceforge.net Subject: Re: [Mspgcc-users] sleep mode power consumption The answer is the normal power source is an unregulated 10v that feeds a switching DC-DC converter to generate 5v for other components, and a 3v regulator for the MSP. The DC-DC converter itself draws more power than the MSP itself, but in shutdown mode it draws essentially no power. Thomas W. Carley wrote: >My question to you is: Why are you using a capacitor to power the msp430? >Why not just us the normal power source? If you are trying to turn off >something else, can you just shut off power AFTER the msp430? > >-----Original Message----- >From: mspgcc-users-ad...@lists.sourceforge.net >[mailto:mspgcc-users-ad...@lists.sourceforge.net] On Behalf Of Kelly Murray >Sent: Tuesday, May 04, 2004 12:55 PM >To: mspgcc-users@lists.sourceforge.net >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 > > > >------------------------------------------------------- >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 > > > > ------------------------------------------------------- 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
