i don't know... you still need the switching transistor/mosfet and a
comparator (at the very minimum), so it probably isn't getting a lot
cheaper (if at all) than a cheap switching IC (there are quite a few
around, like one oldtimer from motorola for under a us$).

but it's probably not too hard to do, if you really want it, or if you have
the pic around anyway. at 4mhz clock and 50khz switching frequency this
gives you a resolution of 5% for the PWM output, which probably is enough.

you still should take care of current limiting. hm... sounds like too much
to handle for which you can have one IC that has it all.

ge

At 14:23 01/11/99 -0500, Larry G. Nelson Sr. wrote:
>I have seen switchmode regulators made with 16C54 processors and some
>analog glue so I don't see why an 84 or 508 couldn't be used.
>
>
>At 08:51 AM 12/15/98 -0800, you wrote:
>>Hi
>>
>>I am working on a low power LCD video monitor for my weekend getaway. Solar
>>and wind power into 12v batteries. I would like to run this 6 volt LCD
>>monitor off 12v and avoid the losses of a linear regulator or the inverter
>>and wall wart. Lm2576A comes to mind but are not available onesies in this
>>town. I need about 5 watts.
>>Has anyone made a switchmode regulator with a c/f84 or a c508?? I probably
>>could use a few of these around the claim and an adjustable model would be
>>a hot item.
>>Any Ideas?
>>Thanks
>>
>>Wil Reeder