Author Topic: ATMega328PU Power consumption at 16Mhz  (Read 3584 times)

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Offline Rick Law

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ATMega328PU Power consumption at 16Mhz
« on: June 06, 2013, 04:52:44 pm »
The datasheet has info on the ATMega328P running at 1Mhz and 8MHz, but not higher.  I need it for 16MHz.

(1) Anyone has info on the CPU @5V power requirement when everything are active?  Everything meaning all IO ports and the ADC doing ADC work.

(2) When burning the Boot loader code, does it draw more?  I recall Old EEProms used to need a lot more juice.

Thanks!
Rick



 

Offline Kostas

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Re: ATMega328PU Power consumption at 16Mhz
« Reply #1 on: June 06, 2013, 05:50:31 pm »
The datasheet has plenty of information, have a look at page 399. In any case, I'd expect the power consumption to be roughly proportional to the operating frequency and (if I'm not mistaken) to the square of the supply voltage.
« Last Edit: June 06, 2013, 05:57:40 pm by Kostas »
 

Offline Rick Law

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Re: ATMega328PU Power consumption at 16Mhz
« Reply #2 on: June 07, 2013, 03:13:02 am »
Thanks!

I stopped after I couldn't find that data in the the electrical characteristic page and didn't go further.

That graph is useful, I should be able to do a good estimate based on how that.

Thanks
Rick
 

Offline westfw

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Re: ATMega328PU Power consumption at 16Mhz
« Reply #3 on: June 07, 2013, 04:43:51 am »
Quote
When burning the Boot loader code, does it draw more?
Now that's an interesting question, and I don't recall seeing anything about it in the datasheet.
Usually writing to flash memory involves using an internal charge pump to generate a higher voltage, and those don't have a reputation for being very "low-power."  But I'm not sure what actions would end up even turning the charge pump on or off...
 

Offline Rick Law

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Re: ATMega328PU Power consumption at 16Mhz
« Reply #4 on: June 07, 2013, 05:15:22 am »
Quote
When burning the Boot loader code, does it draw more?
Now that's an interesting question, and I don't recall seeing anything about it in the datasheet.
Usually writing to flash memory involves using an internal charge pump to generate a higher voltage, and those don't have a reputation for being very "low-power."  But I'm not sure what actions would end up even turning the charge pump on or off...

I used to burn my own EPROM and EEPROM during the early IBM-PC era, they required a good supply of juice -- hence the question to be safe.

Power is less an issue since I have reconsidered what to run my other part of the circuit with.  Initially, I was thinking of powering everything off a single 7805.  My other stuff (to use the ATMega) will use 60mA-70mA.  I just may give "the other stuff" a separate LM317 since I want to run that at about 6-7V and leave the 7805 for the LCD and the ATMega part of the circuit.  That will leave me room to grow.

Once I get my circuit put together, I will try to remember to monitor it some and see what kind of current draw during a boot-loader burn.

 

Offline amyk

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Re: ATMega328PU Power consumption at 16Mhz
« Reply #5 on: June 07, 2013, 01:10:48 pm »
As they say, "it's all in the datasheet"... if you look at page 421 you'll find the "Programming Current vs Vcc" graph. :)
 

Offline Rick Law

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Re: ATMega328PU Power consumption at 16Mhz
« Reply #6 on: June 07, 2013, 03:42:54 pm »
As they say, "it's all in the datasheet"... if you look at page 421 you'll find the "Programming Current vs Vcc" graph. :)

Yeah, it is there.  I was trying to get some info to finalize my next parts-order before I finish the 400+ page of spec.  Apparently I missed some good info there.

Rick
 

Offline madires

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Re: ATMega328PU Power consumption at 16Mhz
« Reply #7 on: June 07, 2013, 05:35:04 pm »
(1) Anyone has info on the CPU @5V power requirement when everything are active?  Everything meaning all IO ports and the ADC doing ADC work.

A single I/O pin can source up to 40mA. So you also need to consider what's attached to each I/O pin.
 

Offline Rick Law

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Re: ATMega328PU Power consumption at 16Mhz
« Reply #8 on: June 08, 2013, 04:01:12 am »
(1) Anyone has info on the CPU @5V power requirement when everything are active?  Everything meaning all IO ports and the ADC doing ADC work.

A single I/O pin can source up to 40mA. So you also need to consider what's attached to each I/O pin.

Good reminder!

Thanks
 


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