I'm sure I've used the LM2678 before -- it's an older chip, but worked  =

well. (National's switchers work well with minimum of futzing).  But I  =

tend towards the newer chips as they run at higher clock speeds and  =

passives come down in size, bringing footprint and cost down.  Their  =

webench tool gives you an estimated BOM cost so that's a good place to  =

look for a net answer.

Alternatively, isn't there some type of protection mechanism you could  =

put in?  Or perhaps change to a custom power connector?

Cheers,
-Neil.



Quoting Philip Pemberton <piclist@philpem.me.uk>:

> PICdude wrote:
>> How about National Semi's LM22678-5.0?  Simple and relatively low
>> cost, but I'm sure they'll have others with a lower parts cost (though
>> more components).
>>
>> http://www.national.com/pf/LM/LM22678.html
>
> That's the part I've been looking at -- =A36 in singles and not much less
> in quantity until you get to >1k-off...
>
> Its brothers, the LM2679 and LM2678, seem to be considerably cheaper.
> They're still =A36 in 1-off, but order ten of them and that's almost
> halved. Total cost of about =A38 for a pretty decent 5V SMPSU that'll take
> anything from 8V to 40V on the input...
>
> And I doubt anyone's likely to have a >40V PSU with a 5.5x2.5mm DC power
> plug on it :)
>
> --
> Phil.
> piclist@philpem.me.uk
> http://www.philpem.me.uk/
>
> --
> http://www.piclist.com PIC/SX FAQ & list archive
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