Hello, It is very difficult to say why you are losing power without shematics. Estimating the current your sistem is using in power down mode is about 1000 times higher as expected to be for MSP430 (about 2mA). As I said, hardly to say why you are losing power, but did you check that the current is not leaking back to the regulator that is feeding cap ?
Regards Saso > --__--__-- > > Message: 10 > From: "Thomas W. Carley" <tcar...@eng.umd.edu> > To: <mspgcc-users@lists.sourceforge.net> > Subject: RE: [Mspgcc-users] sleep mode power consumption > Date: Tue, 4 May 2004 13:27:03 -0400 > Reply-To: mspgcc-users@lists.sourceforge.net > > 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=20 > >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. =20 > > > > The strange thing is that when I monitor the > >voltage after power-down, the cap is loosing voltage rather quickly,=20 > >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. =20 > > > >My guess is that perhaps this behavior is "just lucky", that at 1.66v=20 > >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,=20 > >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=20 > >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.=20 > >Take an Oracle 10g class now, and we'll give you the exam FREE.=20 > >http://ads.osdn.com/?ad_id=3D3149&alloc_id=3D8166&op=3Dclick > >_______________________________________________ > >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.=20 > >Take an Oracle 10g class now, and we'll give you the exam FREE.=20 > >http://ads.osdn.com/?ad_id=3D3149&alloc_id=3D8166&op=3Dclick > >_______________________________________________ > >Mspgcc-users mailing list > >Mspgcc-users@lists.sourceforge.net > >https://lists.sourceforge.net/lists/listinfo/mspgcc-users > > > > > > =20 > > > > > > > ------------------------------------------------------- > 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.=20 > http://ads.osdn.com/?ad_id=3D3149&alloc_id=3D8166&op=3Dclick > _______________________________________________ > Mspgcc-users mailing list > Mspgcc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/mspgcc-users > > > > > --__--__-- > > _______________________________________________ > Mspgcc-users mailing list > Mspgcc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/mspgcc-users > > > End of Mspgcc-users Digest
