Forums

Re: Supply Current of LPC213x

Started by Owen Mooney February 3, 2005
Well - this all rips my socks!!

I put a post in a few weeks ago asking about power consumption of the LPC213x series
for use in a data logger.

Robert said then about 150uA. This was too much for a logger with a 10 year battery life on a Lithium.

So - I have just done a layout using a PIC !

Now I understand the latest run of chips is about 50uA. Quite some difference, and worth while ripping the PIC out of the circuit and putting in an LPC2132

Please confirm. For an LPCLPC213x series microprocessor with 32768 Xtal running powern consumption is 50+18uA in Powerdown mode and when I wake up from an external interupt I can read the current Xtal osc value in the CTC register ?

If so I will rip out the PIC anbd use one of these - even if I have to go to a C size cell.

What is the expected power consumptin of these devices in future production runs?

Owen Mooney Date: Wed, 02 Feb 2005 14:29:09 -0000
From: "tah2k" <>
Subject: Re: Supply Current. Lots additional information I didn't see an explanantion for the 350uA sleep current or my
questions 1 and 2 concerning the I/O. Do I need to try a new device
on the evaluation board?

50uA sleep current is perfect, 140uA is tolerable, and 350uA is a
show stopper.

--- In , "philips_apps" <philips_apps@y...>
wrote:

>>
>> Tim,
>>
>> I guess the 350 mA (the "m" should be a "u")was a typo. What you
>> measured in power down for the RTC is correct between 15 and 20
uAs.

>> Logic in this process needs to run at 1.8V 10 %. A pin like Vbat

>> needs a wider spec and a different voltage. The spec for Vbat will be

>> significantly extended to probably 2.0V-3.6V (characterization is
>> ongoing). To not damage the logic we need to convert the external
>> voltage down to 1.8V The converter uses most of the 18 uAs you
measured.

>> The higher current during active mode is due to an chip failure on the

>> first devices, which have been used to build evaluation boards. New
>> devices will not draw higher current during active mode on Vbat but
>> still draw the 15-20 uAs.
>>
>> THIS INFORMATION IS SPECIFIC FOR THE LPC2130 series
>> Power down current on the first devices was measured around 140
uAs,

>> keeping all the RAM intact. Our latest lot with some fixes brings this

>> value down to approx 50 uAs.
>> While this value might be too high for some of you, it might be
good

>> enough for others and it is for sure a lot better than the previous
>> option to go into idle mode using the RTC.
>>
>> Comparing an ARM build in 0.18um process to an AVR, PIC, MSP430 or
you

>> name them is really comparing apples to oranges. New processes enable

>> the chip vendors to put more memory and build faster devices but the

>> leakage goes up.
>>
>> In the end the only thing I can tell you, this is as good as it
gets

>> right now. Will let everybody know if we find ways to improve the
>> power down behavior. Keep in mind that active current is as low or
>> lower than an 8-bit running at the same clock rate delivering a lot
>> less performance.
>>
>> Regards, Robert
>>
>> --- In , "tah2k" <tah2k@y...> wrote: >>> >
>>> > I finally got to the point of shutting down the LPC2138 on the
>>
>>
Keil

>>> > development board. Battery life is critical to my application,
>>> > therefore I need to verify the sleep specification. At room
>>> > temperature, with all I/O configured as input except for JTAG, I
>>
>>
am

>>> > measuring 350mA just on the VDD pins! Far from 10uA. All
>>
>>
peripheral

>>> > clocks are disabled except the RTC which is configured to use
>>
>>
the

>>> > 32kHz.
>>> >
>>> > FYI:
>>> > Vbat: ~31uA while processor is on, ~18uA during powerdown. (Just
>>
>>
for

>>> > the RTC?!?!)
>>> >
>>> > When it comes to sleep current issues, the first thing vendors
>>> > usually question is the I/O state. The following are the
>>
>>
relevant

>>> > register values:
>>> >
>>> > PINSEL0: 0x0
>>> > PINSEL1: 0x0
>>> > PINSEL2: 0x4
>>> >
>>> > IODIR0: 0x0
>>> > IODIR1: 0x0
>>> >
>>> > IOPIN0: 0x7EFFF7F8
>>> > IOPIN1: 0x03FF0000
>>> >
>>> > I'm puzzled about the I/O:
>>> > 1.) The IOPIN register does not necessarily reflect the state of
>>
>>
the

>>> > I/O line. For example, P0.4 is not connected on the Keil board.
>>> > Since this pin is configured as an input, I would suspect the
>>> > voltage on the pin to reflect the internal pullup, but it
>>
>>
measures

>>> > 0V. Even more puzzling, IOPIN0 states this input is high. Go
>>
>>
figure.

>>> >
>>> > 2.) Another concern: P0.31 is not connected, but configured as
>>
>>
an

>>> > input. If I measure the pin voltage it is 2.3 instead of 3.3V.
>>
>>
This

>>> > is also true for P1.16-23 and P1.24-25. Could I be leaking
>>
>>
current

>>> > through the pullup resistor?
>>> >
>>> > -Tim
>>
>>
>> --- snip -----


An Engineer's Guide to the LPC2100 Series


--- In , Owen Mooney <ojm@s...> wrote:
---snip ----

Owen,

when we designed the LPC2130 series we expected to see Ipd in the
neighborhood of 50 uAs. Unfortunately the first lot came out with an
average of 150 uAs and we were all p.....ed.
There were 2 minor changes to the latest rev "A" which is not in the
filed yet and now we are measuring the devices between 40 and 60 uAs.
This does not include the 15-20 uAs for Vbat as you pointed out
correctly. Also keep in mind that a current from Vbat will also be
drawn during active mode. The rev "A" will draw the same current from
Vbat no matter teh CPU is active or not. The first devices that you
would have right now draw much higher current while the CPU is running
proportional to bus activity.

Ipd is a very difficult value to specify in this process because small
changes in the process will move the point where the Ipd takes off
based on temperature from around 70 C to a temp close to 25C. In this
case Ipd goes up.

If you look in different specifications also from competitors selling
highly integrated ARM chips, you will see a significant difference
between typical Ipd and max Ipd because of this big temperature effect.

Hope this little background information helps,

It's late here, good night, Robert > Robert said then about 150uA. This was too much for a logger with a
10 year battery life on a Lithium.
>
> So - I have just done a layout using a PIC !
>
> Now I understand the latest run of chips is about 50uA. Quite some
difference, and worth while ripping the PIC out of the circuit and
putting in an LPC2132
>
> Please confirm. For an LPCLPC213x series microprocessor with 32768
Xtal running powern consumption is 50+18uA in Powerdown mode and when
I wake up from an external interupt I can read the current Xtal osc
value in the CTC register ?
>
> If so I will rip out the PIC anbd use one of these - even if I have
to go to a C size cell.
>
> What is the expected power consumptin of these devices in future
production runs?
>
> Owen Mooney

---- snip ---




My LPC2138 RTC is drawing ~16uA through Vbat, nice. Your mileage may
vary.

Richard

--- In , Owen Mooney <ojm@s...> wrote:
> Well - this all rips my socks!!
>
> I put a post in a few weeks ago asking about power consumption of
the LPC213x series
> for use in a data logger.
>
> Robert said then about 150uA. This was too much for a logger with a
10 year battery life on a Lithium.
>
> So - I have just done a layout using a PIC !
>
> Now I understand the latest run of chips is about 50uA. Quite some
difference, and worth while ripping the PIC out of the circuit and
putting in an LPC2132
>
> Please confirm. For an LPCLPC213x series microprocessor with 32768
Xtal running powern consumption is 50+18uA in Powerdown mode and when
I wake up from an external interupt I can read the current Xtal osc
value in the CTC register ?
>
> If so I will rip out the PIC anbd use one of these - even if I have
to go to a C size cell.
>
> What is the expected power consumptin of these devices in future
production runs?
>
> Owen Mooney > Date: Wed, 02 Feb 2005 14:29:09 -0000
> From: "tah2k" <tah2k@y...>
> Subject: Re: Supply Current. Lots additional information > I didn't see an explanantion for the 350uA sleep current or my
> questions 1 and 2 concerning the I/O. Do I need to try a new device
> on the evaluation board?
>
> 50uA sleep current is perfect, 140uA is tolerable, and 350uA is a
> show stopper.
>
> --- In , "philips_apps" <philips_apps@y...>
> wrote:
>
> >>
> >> Tim,
> >>
> >> I guess the 350 mA (the "m" should be a "u")was a typo. What you
> >> measured in power down for the RTC is correct between 15 and 20
> >
> >
> uAs.
>
> >> Logic in this process needs to run at 1.8V 10 %. A pin like
> >
> >
> Vbat
>
> >> needs a wider spec and a different voltage. The spec for Vbat will
> >
> >
> be
>
> >> significantly extended to probably 2.0V-3.6V (characterization is
> >> ongoing). To not damage the logic we need to convert the external
> >> voltage down to 1.8V The converter uses most of the 18 uAs you
> >
> >
> measured.
>
> >> The higher current during active mode is due to an chip failure on
> >
> >
> the
>
> >> first devices, which have been used to build evaluation boards. New
> >> devices will not draw higher current during active mode on Vbat but
> >> still draw the 15-20 uAs.
> >>
> >> THIS INFORMATION IS SPECIFIC FOR THE LPC2130 series
> >> Power down current on the first devices was measured around 140
> >
> >
> uAs,
>
> >> keeping all the RAM intact. Our latest lot with some fixes brings
> >
> >
> this
>
> >> value down to approx 50 uAs.
> >> While this value might be too high for some of you, it might be
> >
> >
> good
>
> >> enough for others and it is for sure a lot better than the previous
> >> option to go into idle mode using the RTC.
> >>
> >> Comparing an ARM build in 0.18um process to an AVR, PIC, MSP430 or
> >
> >
> you
>
> >> name them is really comparing apples to oranges. New processes
> >
> >
> enable
>
> >> the chip vendors to put more memory and build faster devices but
> >
> >
> the
>
> >> leakage goes up.
> >>
> >> In the end the only thing I can tell you, this is as good as it
> >
> >
> gets
>
> >> right now. Will let everybody know if we find ways to improve the
> >> power down behavior. Keep in mind that active current is as low or
> >> lower than an 8-bit running at the same clock rate delivering a lot
> >> less performance.
> >>
> >> Regards, Robert
> >>
> >> --- In , "tah2k" <tah2k@y...> wrote:
> >
> >
> >>> >
> >>> > I finally got to the point of shutting down the LPC2138 on the
> >>
> >>
> Keil
>
> >>> > development board. Battery life is critical to my application,
> >>> > therefore I need to verify the sleep specification. At room
> >>> > temperature, with all I/O configured as input except for JTAG, I
> >>
> >>
> am
>
> >>> > measuring 350mA just on the VDD pins! Far from 10uA. All
> >>
> >>
> peripheral
>
> >>> > clocks are disabled except the RTC which is configured to use
> >>
> >>
> the
>
> >>> > 32kHz.
> >>> >
> >>> > FYI:
> >>> > Vbat: ~31uA while processor is on, ~18uA during powerdown. (Just
> >>
> >>
> for
>
> >>> > the RTC?!?!)
> >>> >
> >>> > When it comes to sleep current issues, the first thing vendors
> >>> > usually question is the I/O state. The following are the
> >>
> >>
> relevant
>
> >>> > register values:
> >>> >
> >>> > PINSEL0: 0x0
> >>> > PINSEL1: 0x0
> >>> > PINSEL2: 0x4
> >>> >
> >>> > IODIR0: 0x0
> >>> > IODIR1: 0x0
> >>> >
> >>> > IOPIN0: 0x7EFFF7F8
> >>> > IOPIN1: 0x03FF0000
> >>> >
> >>> > I'm puzzled about the I/O:
> >>> > 1.) The IOPIN register does not necessarily reflect the state of
> >>
> >>
> the
>
> >>> > I/O line. For example, P0.4 is not connected on the Keil board.
> >>> > Since this pin is configured as an input, I would suspect the
> >>> > voltage on the pin to reflect the internal pullup, but it
> >>
> >>
> measures
>
> >>> > 0V. Even more puzzling, IOPIN0 states this input is high. Go
> >>
> >>
> figure.
>
> >>> >
> >>> > 2.) Another concern: P0.31 is not connected, but configured as
> >>
> >>
> an
>
> >>> > input. If I measure the pin voltage it is 2.3 instead of 3.3V.
> >>
> >>
> This
>
> >>> > is also true for P1.16-23 and P1.24-25. Could I be leaking
> >>
> >>
> current
>
> >>> > through the pullup resistor?
> >>> >
> >>> > -Tim
> >>
> >>
> >> --- snip -----
> >
> >




for a very low power datalogger have a look at msp430... --- In , Owen Mooney <ojm@s...> wrote:
> Well - this all rips my socks!!
>
> I put a post in a few weeks ago asking about power consumption of
the LPC213x series
> for use in a data logger.
>
> Robert said then about 150uA. This was too much for a logger with a
10 year battery life on a Lithium.
>
> So - I have just done a layout using a PIC !
>
> Now I understand the latest run of chips is about 50uA. Quite some
difference, and worth while ripping the PIC out of the circuit and
putting in an LPC2132
>
> Please confirm. For an LPCLPC213x series microprocessor with 32768
Xtal running powern consumption is 50+18uA in Powerdown mode and when
I wake up from an external interupt I can read the current Xtal osc
value in the CTC register ?
>
> If so I will rip out the PIC anbd use one of these - even if I have
to go to a C size cell.
>
> What is the expected power consumptin of these devices in future
production runs?
>
> Owen Mooney > Date: Wed, 02 Feb 2005 14:29:09 -0000
> From: "tah2k" <tah2k@y...>
> Subject: Re: Supply Current. Lots additional information > I didn't see an explanantion for the 350uA sleep current or my
> questions 1 and 2 concerning the I/O. Do I need to try a new device
> on the evaluation board?
>
> 50uA sleep current is perfect, 140uA is tolerable, and 350uA is a
> show stopper.
>
> --- In , "philips_apps" <philips_apps@y...>
> wrote:
>
> >>
> >> Tim,
> >>
> >> I guess the 350 mA (the "m" should be a "u")was a typo. What you
> >> measured in power down for the RTC is correct between 15 and 20
> >
> >
> uAs.
>
> >> Logic in this process needs to run at 1.8V 10 %. A pin like
> >
> >
> Vbat
>
> >> needs a wider spec and a different voltage. The spec for Vbat
will
> >
> >
> be
>
> >> significantly extended to probably 2.0V-3.6V (characterization is
> >> ongoing). To not damage the logic we need to convert the external
> >> voltage down to 1.8V The converter uses most of the 18 uAs you
> >
> >
> measured.
>
> >> The higher current during active mode is due to an chip failure
on
> >
> >
> the
>
> >> first devices, which have been used to build evaluation boards.
New
> >> devices will not draw higher current during active mode on Vbat
but
> >> still draw the 15-20 uAs.
> >>
> >> THIS INFORMATION IS SPECIFIC FOR THE LPC2130 series
> >> Power down current on the first devices was measured around 140
> >
> >
> uAs,
>
> >> keeping all the RAM intact. Our latest lot with some fixes
brings
> >
> >
> this
>
> >> value down to approx 50 uAs.
> >> While this value might be too high for some of you, it might be
> >
> >
> good
>
> >> enough for others and it is for sure a lot better than the
previous
> >> option to go into idle mode using the RTC.
> >>
> >> Comparing an ARM build in 0.18um process to an AVR, PIC, MSP430
or
> >
> >
> you
>
> >> name them is really comparing apples to oranges. New processes
> >
> >
> enable
>
> >> the chip vendors to put more memory and build faster devices but
> >
> >
> the
>
> >> leakage goes up.
> >>
> >> In the end the only thing I can tell you, this is as good as it
> >
> >
> gets
>
> >> right now. Will let everybody know if we find ways to improve the
> >> power down behavior. Keep in mind that active current is as low
or
> >> lower than an 8-bit running at the same clock rate delivering a
lot
> >> less performance.
> >>
> >> Regards, Robert
> >>
> >> --- In , "tah2k" <tah2k@y...> wrote:
> >
> >
> >>> >
> >>> > I finally got to the point of shutting down the LPC2138 on
the
> >>
> >>
> Keil
>
> >>> > development board. Battery life is critical to my
application,
> >>> > therefore I need to verify the sleep specification. At room
> >>> > temperature, with all I/O configured as input except for
JTAG, I
> >>
> >>
> am
>
> >>> > measuring 350mA just on the VDD pins! Far from 10uA. All
> >>
> >>
> peripheral
>
> >>> > clocks are disabled except the RTC which is configured to use
> >>
> >>
> the
>
> >>> > 32kHz.
> >>> >
> >>> > FYI:
> >>> > Vbat: ~31uA while processor is on, ~18uA during powerdown.
(Just
> >>
> >>
> for
>
> >>> > the RTC?!?!)
> >>> >
> >>> > When it comes to sleep current issues, the first thing
vendors
> >>> > usually question is the I/O state. The following are the
> >>
> >>
> relevant
>
> >>> > register values:
> >>> >
> >>> > PINSEL0: 0x0
> >>> > PINSEL1: 0x0
> >>> > PINSEL2: 0x4
> >>> >
> >>> > IODIR0: 0x0
> >>> > IODIR1: 0x0
> >>> >
> >>> > IOPIN0: 0x7EFFF7F8
> >>> > IOPIN1: 0x03FF0000
> >>> >
> >>> > I'm puzzled about the I/O:
> >>> > 1.) The IOPIN register does not necessarily reflect the state
of
> >>
> >>
> the
>
> >>> > I/O line. For example, P0.4 is not connected on the Keil
board.
> >>> > Since this pin is configured as an input, I would suspect the
> >>> > voltage on the pin to reflect the internal pullup, but it
> >>
> >>
> measures
>
> >>> > 0V. Even more puzzling, IOPIN0 states this input is high. Go
> >>
> >>
> figure.
>
> >>> >
> >>> > 2.) Another concern: P0.31 is not connected, but configured
as
> >>
> >>
> an
>
> >>> > input. If I measure the pin voltage it is 2.3 instead of
3.3V.
> >>
> >>
> This
>
> >>> > is also true for P1.16-23 and P1.24-25. Could I be leaking
> >>
> >>
> current
>
> >>> > through the pullup resistor?
> >>> >
> >>> > -Tim
> >>
> >>
> >> --- snip -----
> >
> >



Thanks

And the Power down current? or arn't you going there. I beleve Vbat gets
added to VCC

Owen

>
>My LPC2138 RTC is drawing ~16uA through Vbat, nice. Your mileage may
>vary.
>
>Richard
>




Nah !

Thanks Jan, but I've had a look at some of these and I don't think this one supports SPI (for logging storage)

Also I've painted myself into a development corner in the past (you know - can i get a bit more ram or a bit more rom or a bit more speed) and i'm not doing it again. I would rather pay for a C Lithium which will give 10 years operation.

Owen

From: "Jan Szymanski" <>
Subject: for a very low power datalogger have a look at msp430...




No, that is 16uA with Vcc off/removed. Yes, I believe you are
correct, Vbat current gets added to Vcc current. Perhaps the apps
types can add to this, I know there were some peculiarities.

Richard --- In , Owen Mooney <ojm@s...> wrote:
> Thanks
>
> And the Power down current? or arn't you going there. I beleve Vbat
gets
> added to VCC
>
> Owen
>
> >
> >My LPC2138 RTC is drawing ~16uA through Vbat, nice. Your mileage may
> >vary.
> >
> >Richard
> >