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Re: LPC213x supply current

2005-03-28 by wittrockjeff

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

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