Re: Universal PIC switchmode status report

On Fri, 06 Feb 2009 18:48:10 GMT, Jan Panteltje
<pNaonStpealmtje@xxxxxxxxx> wrote:


Hammy, hysteretic is indeed cool, no other stabilisation RC networks needed.

Yes it is,you cant beat it for simplicity.The only downsides to it are
the funky output ripple but AND8284-D shows how you can use feedfoward
to reduce it.

http://www.onsemi.com/pub_link/Collateral/AND8284-D.PDF

The other thing is the darlington output makes it somewhat slow
compared to other controllers and higher quiescent current. But if
they tweaked it to much they would have to jack the price up so for 50
cents it's definetly better then using a 7800 series.Particularily if
you have a large input to output difference.

I looked up the NCP40363 too, and the MC34063A.pdf, the soft start I have
now, makes the PIC solution a bit better I think, the MCP3063 has a slight overshoot
at startup, see page 7 of the datasheet.

Yes it doesnt have a soft start function.

The question remains, how will FLASH and EEPROM stay error free over time?
One can make a checksum, and test against that at power up, or if the memory
is big enough keep 2 copies of the code and compare at startup.
You know how they dig up dinosaurs and old pots and pans and stuff,
maybe thousands of years from now, when they dig up stuff from our civilisation,
they will not be able to even try any of the zillion gadgets, as all FLASH will be dead :-)


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