Lpc2000

Hi Jeff,

don't know exactly what kind of DC/DC but no external components
required. I saw it in one of Philips' presentations.
Why no 1.8V any more? Our application is fine with 3V (not battery
powered though) and we can safe the money for a regulator down to 1.8V.

So, cost savings for thous running from AC :-) but higher current in
power down for battery applications and no 1.8V supply :-(

Bob

--- In lpc2000@yahoogroups.com, "wittrockjeff" <jwittrock@m...> wrote:
> 
> Hello Bob,
> 
> One other thing I was wondering about.  You mention the LPC2138 uses 
> an internal DC/DC converter.  Is this shown anywhere in the 
> datasheet or user guide.  I may have just missed it.  
> 
> Can you tell me is this a charge pump DC/DC converter or an inductor 
> based.  If its inductor based, is there a requirement for an 
> external inductor?  Or maybe its a linear regulator?
> 
> Sorry if this is already shown in the documentation somewhere and I 
> missed it.  I was just wondering why philips did away with bringing 
> a 1.8V core voltage out on the pins.  I kind of wished they had left 
> it like the 210x, my battery powered app could use the lower core 
> voltage to advantage.
> 
> Thanks again,
> Jeff
> 
> 
> 
> --- In lpc2000@yahoogroups.com, "wittrockjeff" <jwittrock@m...> 
> wrote:
> > 
> > Hello Bob,
> > 
> > Very helpful information.  
> > 
> > Thanks so much
> > -Jeff
> > 
> > 
> > --- In lpc2000@yahoogroups.com, "lpc2100_fan" <lpc2100_fan@y...> 
> > wrote:
> > > 
> > > Hi Jeff,
> > > 
> > > some measurement from our team:
> > > Running at 60 MHz with peripherals enabled from Flash approx. 45 
> > mAs,
> > > running from RAM 52/53 mAs, external 12 MHZ PLL *5 to 60 MHz. All
> > > preipehrals were anabled.
> > > 
> > > The core still uses 1.8V but the 1.8V are generated by a DC/DC
> > > converter inside the chip.
> > > 
> > > Specification is 3V for function, reducing the voltage lower 
> than 
> > that
> > > is OK but we want to use the Brown Out Detect which hit somewhere
> > > around 2.9V.  Absolute no problem until the BOD hits. We even 
> tried 
> > to
> > > just generate an interrupt with BOD at 2.9 and the device worked 
> > down
> > > to approx. 2.6V where the lower threshold BOD hit us with a 
> Reset. 
> > > As far as our tests can tell, the LPC2138 works actually down to 
> > 2.6V
> > > but we won't try that. The upper level BOD will be used in our 
> > design
> > > to save a few critical parameters into the Flash and then we go 
> to
> > > Power Down. 
> > > 
> > > hth Bob
> > > 
> > > 
> > > --- In lpc2000@yahoogroups.com, "wittrockjeff" <jwittrock@m...> 
> > wrote:
> > > > 
> > > > Does anyone have some rough estimates of supply current for 
> the 
> > > > LPC213x family running at 60MHz with peripherals enabled.  In 
> > > > particular I want to use the LPC2138 device.
> > > > 
> > > > Active mode supply current is still <TBD> in the datasheet.
> > > > 
> > > > Since this device uses 3.3V for both the core and I/O, I'm 
> > wondering 
> > > > how close it will be to the LPC210x family.  Does the LPC213x 
> > still 
> > > > use 1.8V for the core, and just an internal regulator?
> > > > 
> > > > As an aside, I'm also wondering if the part will remain 
> > functional 
> > > > (reliable?) if the supply voltage drops to 2.85V?
> > > > 
> > > > I would measure one myself, but don't have a board yet, just 
> some 
> > > > sample parts.
> > > > 
> > > > Thanks,
> > > > Jeff W