Which one is the very low power microcontroller

[localcrack]

I just want to build one battery operated application so I needs very low power microcontroller. As doing a research I found following one

1) STM8L
2) STM32L
3) MSP430

If you know any other one that have very low power consumption per Mhz then please suggest me.

[Magnox]

How about 30µA per MHz?

http://www.microchip.com/pagehandler/en-us/technology/xlp/

[TrimmedProbes]

Also, check out if any of the processors have an ultra low power mode or sleep mode.  The advantage here is that you may be able to switch to this mode when the application is not doing much and wake up the processor when it needs to do some work.
Regards

[mare69]

How about energy micro EFM32?

http://www.energymicro.com/products/



Here's a subVt article:
http://eetweb.com/Embedded-systems-start-living-sub-threshold-world/

[Gallymimu]

+1 for microchip XLP processors (warning I am a microchip fanboy and design partner!).  The 24F series processors have some XLPs in their lineup.  They are pretty potent for ultra low power processors.  It of course depends on your specific needs though.

[localcrack]

Anybody experienced with this one ?

[Gallymimu]

Anybody experienced with this one ?

One of our customers is using a PIC24F XLP for low power sensor data acquisition and ANT+ communication running on a coin cell.  It collects and transmits data every few seconds.  It runs 200-350 days on a coin cell.  It makes heavy use of sleep mode and wakes up to run the ADC and communicate to the ANT+ transceiver.

[FTL]

Another vote for PIC XLP stuff. Some of them can sleep while the ADC is converting. You can set the clock speed to the minimum you need to reduce power as most of the power usage is rated in uA per Hz.

When in sleep mode the current consumption is probably more than the parasitic currents caused by oil from fingerprints across two close traces that have a potential between them.

[solutions]

Quantify with nA/MHz, and nA in sleep mode, or your opinion is just that - an opinion

[Ichan]

I just want to build one battery operated application so I needs very low power microcontroller.

What battery voltage it will be?

I am searching for microcontroller that can be run from 1.5V battery natively (without using internal charge pump), found only TI MSP430 low valtage series that meet this voltage level. Is that true?

-ichan

[Gallymimu]

As an example the PIC24F04KA201:
running at 1.8V
.5 MIPS @ 195 uA
25nA sleep
A/D will convert during sleep

Not sure how this compares to the offerings of the other manfs

[mare69]

I am searching for microcontroller that can be run from 1.5V battery natively (without using internal charge pump), found only TI MSP430 low valtage series that meet this voltage level. Is that true?

-ichan

Yes, I run MSP430L092 from a single HR8D425. Works down to 1,05V @1MHz.

[CocaCola]

The sleep mode on many of these new micros is far less than the self drain of the battery just sitting there on the shelf, it's really amazing how long they will last if the program is tight and the circuit is tight...

[Gallymimu]

The sleep mode on many of these new micros is far less than the self drain of the battery just sitting there on the shelf, it's really amazing how long they will last if the program is tight and the circuit is tight...

You sure they are that good?  A little looking suggests that Lithium coin cells loose about 1% per year.  So a CR2052 (160mAH-200mAH coin cell) would lose 1.6mAH per year or a draw of 3.5nA over the 455,000 hours per year.  Are some of these procs in the sub nA sleep range?

I pulled some of the assumptions from here:
http://www.maximintegrated.com/app-notes/index.mvp/id/505
http://www.microbattery.com/tech-maxell-lithium.htm

I did see some rayovac datasheets that suggest only .3% self discharge
http://www.rayovac.com/Technical%20OEM/~/media/Rayovac/Files/Product%20Guides/pg_lithium.ashx
which would put it down at 1nA self discharge.

Posted on: October 11, 2012, 11:51:07 23:51 - Automerged

What battery voltage it will be?

I am searching for microcontroller that can be run from 1.5V battery natively (without using internal charge pump), found only TI MSP430 low valtage series that meet this voltage level. Is that true?
-ichan

Just curious, why 1.5V rather than 3V Lithium?  I only ask because you usually see 3V Lithiums used in low discharge long life applications.

[CocaCola]

You sure they are that good?

Yes, you are basing your contrary results on a single cell chemistry and limited range of batteries to do your comparison...  Not all applications will use those lithium batteries in fact many won't, standard alkaline and even lead/acid is still industry standard in many applications...  Also the environmental conditions will play a huge part in the ambient battery drain, datasheets always focus on ideal situations not reality, and this can have a huge effect...  Yes, there are exceptions to what I stated but my statement still stands and is valid...

The Microchip XLP can be as low as 9nA that is well below the self drain of a huge portion of consumer batteries...

[Gallymimu]

Yes, you are basing your contrary results on a single cell chemistry and limited range of batteries to do your comparison...  Not all applications will use those lithium batteries in fact many won't, standard alkaline and even lead/acid is still industry standard in many applications...  Also the environmental conditions will play a huge part in the ambient battery drain, datasheets always focus on ideal situations not reality, and this can have a huge effect...  Yes, there are exceptions to what I stated but my statement still stands and is valid...

The Microchip XLP can be as low as 9nA that is well below the self drain of a huge portion of consumer batteries...

Ah gotcha.  I was thinking more along the lines of serious low power application, not typical batteries that aren't designed for low power.  Of course a lead acid battery or a NiCd battery will be dead in no time flat without any help!  Thanks for the clarification.  I thought maybe you had identified processors with much lower sleep current than the XLPs!  I wasn't trying to beat you up BTW but rather to see what I was missing out on.

I think my running IPOD might be lower drain than a large lead acid battery sitting in a hot room

[CocaCola]

Understand...

A lot of my projects are designed to run on consumer batteries like AA, AAA and 9V...  Thus my initial statement...

[localcrack]

Let's try with Microchip XLP products as it easily available and cheaper price.

[alexisnik]

In general, there are other very important parts of a circuit when you design it for low power:

1. Power. Converters, LDOs, DC/DC, even Mosfets, take up power, compared to that of the microprocessor, even if in sleep mode
2. PROGRAMMING. YES! You can drop from hundreds of microAmps (uA) to 1-2 uA, changing pin configurations etc.
3. Wake up events. RTC, ADC level, accelerometers, etc.

My point is not to look just at the processor power, but the whole system.

The Microchip XLP can be as low as 9nA that is well below the self drain of a huge portion of consumer batteries...

This seems too little, are you sure??? Can you point at a specific model?

[CocaCola]

This seems too little, are you sure??? Can you point at a specific model?

Yep, I'm sure...  PIC18F47J53

http://www.microchip.com/pagehandler/en-us/technology/xlp/

[flo0319]

Yes, but only in sleep mode probably with all peripherals shutdown. In run mode the consumption start from 30uA/MHz.

MCU power consumption is strictly dependent of application (peripherals used, clock speed, software optimization, external passive/active components )

[thegoodjames]

MCU power consumption is strictly dependent of application (peripherals used, clock speed, software optimization, external passive/active components )

I agree, it varies a lot depending on what's actually on and what's off. Core consumption tells part of the story

[sarah90]

I have been impressed by the extensive msp430 power management facilities. Athough I am a hardcore pic fan, I do look at the msp430 more and more. Also very good price/capability ratio with the msp430.

[mare69]

Just returned from electronica fair. I saw CSEM ultra low power microcontrollers (or MCU building blocks). Here's one flyer http://www.csem.ch/docs/Show.aspx?id=6105 You may contact Mr. Simon Gray, [email protected] for more details.