Re: 5V regulator for batteries cheap efficient?

From: Mike Harrison (mike_at_whitewing.co.uk)
Date: 02/12/05 

Date: Sat, 12 Feb 2005 11:35:51 GMT

On 11 Feb 2005 21:25:58 -0800, u035m4i02@sneakemail.com wrote:

>I know I can't have everything, but I'm going to ask for it anyway.
>
>The circuit is 8 or so opamps, comparators, and logic circuits driven
>by +/-5 V. It will run on batteries. Is there a comparatively cheap
>(double the price? maybe triple) but more efficient regulator than the
>7805/7905 for this application? i don't want the batteries throwing
>all their energy into heatsinks and running out in 5 minutes. if
>switching, it's got to have decent noisefreeness. noise above the
>audio band is fine.
>
>Any suggestions? the lm2940 looks promising, but you folks probably
>know better...

How much does your product draw..? If more than a few tens of mA then only a switcher will give you
significantly better efficiency. If a few mA, then look at the Holtek HT7150 - quiescent a couple
of microamps, and takes input up to 24V. About US$0.30 from memory.
Also look at OnSemi 78LC/FC series - similar efficiency but lower input range

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