[time-nuts] Switching regulator replacement for 7805
jimlux at earthlink.net
Sun Dec 4 16:34:36 EST 2016
On 12/4/16 1:09 PM, Attila Kinali wrote:
> On Sun, 4 Dec 2016 15:45:55 -0500
> Bob Camp <kb8tq at n1k.org> wrote:
>> Given that the parts to build one are fairly easy to get and that we likely have “nutty”
>> EMI requirements. Maybe a small board that drops into a 78xx footprint is the
>> better solution.
> I don't fully agree. To go full "nutty" you would want to use the chips
or buy a few of each of the commercial modules and test them. They are
an all-in-one solution with all the usual features about overtemp,
What you'd need to do is characterize their noise properties over load
(something not in the datasheet), and then you could design a LC filter
to knock down the rest. Or do the LDO regulator thing.. it's not
entirely clear that a dc/dc followed by a suitable LDO might not come
out ahead of a dc/dc followed by a filter.
Even for time-nuts, I suspect we're not looking to eke out the last
percent of efficiency from 96% to 97%, or handle wildly varying loads,
etc. Nor are we usually looking for absolute minimum parts cost.
More information about the time-nuts