On Fri, 6 Feb 1998 08:34:36 -0500, you wrote:

>I have a battery power PIC application that I have the opportunity to reduce the
> power by running
>the PIC at 3V. I looked at Linear Technology, Maxim, National Semiconductor and
> Harris for a LDO
>micropower 3V regulator and found MAX663 666 and 689. I was hoping for a three
> terminal TO-92
>type part. The circuit has 4 Alkaline cells (6V) and draws 1.4ma @6V at 3V the
> draw is 0.74mA and
>runs continuously until the batteries need replacement.
>
>I don't  any experience using  switching regulators for battery power. Is this a
> viable option or is a
>linear regulator a better choice for battery life.
>
>Any  favorites??
>
>- -Mark
My fave is the Holtek HT10xx series (xx = 50,33,30 etc. ) - very low
dropout, and 1-2uA or so quiescent. Needs virtually no in/out caps for
stability, but load transient response isn't great unless you whack a
few uF on the output. TO-92 or SOT-89 and VERY CHEAP (UKP 0.32
50-off).
Using this with a PIC in sleep is as good as being switched off!
Ricoh, Seiko and Telcom do similar devices in TO-92, SOT23-5 and
SOT-89, but I've found Holtek is easiest to get - the others often had
silly leadtimes (>12 weeks, which in my book means 'forget it'). 
Presumably you need 6V for something else, otherwise 3v straight from
the batteries would be an alternative choice.
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