Lpc2000

At 11:45 AM 4/26/2006 -0300, Xtian Xultz wrote:
>Em Ter 25 Abr 2006 20:55, Robert Adsett escreveu:
> > At 08:04 PM 4/25/2006 -0300, Xtian Xultz wrote:
> > >  Its too dangerous to generate 1.8V (more or less) from the 3.3V with two
> > >diodes in series?
> > >Someone tryed this?
> >
> > Just put in an LDO.  You can get them as small as a sot23 giving you about
> > 90mA with a 30C rise dropping down from the 3V3 supply.
>Thats what I am using, LM317 with SOT23 footprint. What makes me sad is that
>both regulators (one for 3,3 and one for 1,8V) plus the resistors ocuppies
>more space on the board than the LPC itself.

Others have pointed out the use of dual regulators to save space but just 
as important is the use of a fixed voltage regulator.  Unless you are using 
0203's your resistors probably take more room than the regulators.

With a sot23 dual regulator you are down to what? a sot23 and 3 caps?

Reflecting on the past embedded systems's I've built, the power supply has 
almost always been comparable in size to the microcrontroller.  Of course 
most of those has external memory but even so the PS was a significant piece.

Robert

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