Suggestions needed for battery operated circuit

[hemnath]

I am designing a battery operated circuit where the circuit consumes max current of 2mA.

I have used MAX1724 to convert the battery voltage input voltage(0.8V to 3V) to 3.3V output voltage.

Since my circuit consumes 2mA, but DC DC converter consumes more than this(but its quiescent current is very low in terms of uA). Because of the power transfer from lower voltage to higher voltage. It increases the current drawing from the battery and thus reducing the number of hours.

my need is to operate the circuit with the 2 x AA battery for 1500 hours approximately.??
Is it possible? If it is, how to achieve this?

Please help.

 

[BradtheRad]

The 'joule thief' design should suit your purpose.

It can step up a single AA cell to 3.3V.

To provide 2mA, you will draw an average 6mA.
So you can get several hundred hours of use from a AA cell.

 

[hemnath]

if the average current drawn is 6mA as you said, the approximate hours of battery would be 1800mAh(assumed)/6mA => 300 hours. Am i right?

But i would like to have a life of 1500 hours.
Is it possible by any other method?

 

[BradtheRad]

But i would like to have a life of 1500 hours.

You'll need to upgrade to a C or D cell. Even that probably will not give you 1500 hrs.

Or use several AA. If you put three in series then the supply voltage is 4.5V. It is practical to regulate it with a simple zener diode. (No need for a boost converter.) That may give you upwards of 1500 hours.

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Your spec requires several Amp-hours of capacity.

It works out to 9.9 A-Hrs, at 3.3V, 2 mA, 1500 hrs,