With which MSP430? At what sample rate? Continuously, once ina  while, 
at very low power consumption?

there are too many options to answer your question simply. be more 
specific, and help will be easier to provide.

Al

Arunkumar wrote:
> 
> Sir
> How to read ADC samples 
> 
> ----- Original Message ----- 
> From: "Wolfgang Reich" <reich_wolfgang@reic...>
> To: <msp430@msp4...>
> Sent: Wednesday, December 15, 2004 06:19 PM
> Subject: [msp430] Re: DC-DC converter design
> 
> 
> 
>>
>>--- In msp430@msp4..., Frederic Beaulieu <Frb78@y...> wrote:
>>
>>>However, I don't understand how you can obtain a
>>>regulated 3V with an input voltage between 2.5V & 4.2V
>>>(Li-Ion battery).
>>
>>Linear Technology has some very nice synchronous buck/boost 
>>converters, e.g. LTC3440.
>>http://www.linear.com/pc/viewCategory.do?navId=H0,C1,C1003,C1042,C1116
>>
>>
>>
>>>--- onestone <onestone@b...> wrote:
>>>
>>>
>>>>On nearly all my designs I use a regulator of some
>>>>kind, mainly to get 
>>>>the most out of a battery while retaining the same
>>>>supply voltage 
>>>>enabling high speed operation and flash writing. The
>>>>MAX1724 has an 
>>>>extremely low quiescent current at only 1.5uA, but
>>>>is limited to 150mA. 
>>>>IT takes input of 0.8 to 5.5V and comes in a range
>>>>of fixed voltages. 
>>>>For high current I use the MAX1674. It's quiescent
>>>>current is 16uA, but 
>>>>it can output 1A from an input of 0.7V to Vout. It
>>>>works with slight 
>>>>overvoltage.
>>>>
>>>>I get my batteries from Taiwan. 3.3Ah costs me US$7
>>>>in low volume US$5 
>>>>in 100 off. I get mine through a friend in Asia. The
>>>>company is called 
>>>>HEcell. The free trade magazine 'ELECTRONIC
>>>>COMPONENTS ASIA' is an 
>>>>absolute gold mine for stuff like this.
>>>>
>>>>Al
>>>>
>>>>Frederic Beaulieu wrote:
>>>>
>>>>
>>>>>>From: "onestone" <onestone@b...>
>>>>>>
>>>>>>This is not a Li-poly or Li-ion. These output 3.6V
>>>>>
>>>>>and >are capable of 
>>>>>
>>>>>
>>>>>>very high discharge currents at low temperatures.
>>>>
>>>>I
>>>>
>>>>>>regularly use these in systems drawing up to 1A.
>>>>>
>>>>>
>>>>>Which one exactly do you use? Are they expensive?
>>>>>How do you regularize it for a 3V output voltage?
>>>>
>>>>I
>>>>
>>>>>can see for 5V output (switcher) but I'm not sure
>>>>
>>>>for
>>>>
>>>>>3V.
>>>>>
>>>>>
>>>>>
>>>>>>170mA is very high for many >battery 
>>>>>>technologies.
>>>>>>
>>>>>>Al
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>__________________________________ 
>>>>> 
>>>>>
>>>>>
>>>>>
>>>>>.
>>>>>
>>>>> 
>>>>>Yahoo! Groups Links
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>>>>>
>>>>>
>>>>> 
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
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>>>>Now with Pop-Up Blocker. Get it for free!
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>>>
>>>http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/CFFolB/TM
>>>
>>>--------------------------------
>>
>>~->
>>
>>>>
>>>>.
>>>>
>>>> 
>>>>Yahoo! Groups Links
>>>>
>>>>
>>>>    msp430-unsubscribe@msp4...
>>>>
>>>> 
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>>
>>>__________________________________ 
>>>
>>
>>
>>
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On Wed, Dec 15, 2004 at 12:49:55PM -0000, Wolfgang Reich wrote:

> --- In msp430@msp4..., Frederic Beaulieu
<Frb78@y...> wrote:
> > However, I don't understand how you can obtain a
> > regulated 3V with an input voltage between 2.5V & 4.2V
> > (Li-Ion battery).
> 
> Linear Technology has some very nice synchronous buck/boost 
> converters, e.g. LTC3440.
> http://www.linear.com/pc/viewCategory.do?navId=H0,C1,C1003,C1042,C1116

100A No-Load Quiescent Current

Not the best choice for a low power designs ;-)

        Matthias