Forums

LPC213x supply current

Started by wittrockjeff March 25, 2005

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



An Engineer's Guide to the LPC2100 Series


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 , "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




Hello Bob,

Very helpful information.

Thanks so much
-Jeff --- In lpc2000@lpc2..., "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@lpc2..., "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




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@lpc2..., "wittrockjeff" <jwittrock@m...>
wrote:
>
> Hello Bob,
>
> Very helpful information.
>
> Thanks so much
> -Jeff > --- In lpc2000@lpc2..., "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@lpc2..., "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




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@lpc2..., "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@lpc2..., "wittrockjeff" <jwittrock@m...>
> wrote:
> >
> > Hello Bob,
> >
> > Very helpful information.
> >
> > Thanks so much
> > -Jeff
> >
> >
> > --- In lpc2000@lpc2..., "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@lpc2..., "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